Pioneers in Science and Technology Series: Wesley T. Hanson

PIONEERS IN SCIENCE AND TECHNOLOGY SERIES
ORAL HISTORY OF DR. WESLEY HANSON
Interviewed by Clarence Larson
Filmed by Jane Larson
Date Unknown
Transcribed by Jordan Reed
[Pre-interview conversation]
DR. HANSON: You get to test the sound?
MR. LARSON: I’ve already tested it.
DR. HANSON: You’ve already tested it so it’s all right. [microphone feedback] Whoops. Little ring there.
MR. LARSON: All right and she looks at the monitor there.
DR. HANSON: I noticed her name in the, as doing all the work in these things, the earlier things. Let’s see, do I want that buttoned? I guess I do, I don’t care.
MR. LARSON: Now let’s see, I want to move this light so there is nothing on his glasses. [inaudible] Now see, when you turn this way it will, but you won’t ever turn…
DR. HANSON: I should turn more than this far.
MR. LARSON: Yeah. That’s right. So then there is nothing on the glasses.
DR. HANSON: If I can turn over this way, but why would I? Now, tell me when it hits the glasses when I come this way.
MRS. LARSON: Not yet.
DR. HANSON: Not yet?
MR. LARSON: I think I moved it. There!
MRS. LARSON: But that’s too high.
DR. HANSON: I won’t need to go that far anyway. I need to wipe off my glasses. Got little spots from that light over there.
MR. LARSON: Do you want to try the zoom? All right, that looks fine. Well, as I said, we’ll make it run as long as it’s natural. The tape is two hours, but if it runs over that we’ll just put in another tape. That’s all there is to it.
DR. HANSON: I don’t think my life will last more than two hours. (Laughter)
MR. LARSON: Ready, Jane?
MRS. LARSON: Ready. It’s on.
MR. LARSON: Ok, well fine, I think we can now start. Today we have the privilege to interview Dr. W.T. Hanson, whose distinguished career in photographic research has made key contributions to the development to modern color photography and many applications to photography through science, technology and art. It is a privilege to introduce Dr. Hanson. Please proceed, Dr. Hanson.
DR. HANSON: Yes, thank you. Well I might as well start at the beginning.
MR. LARSON: Very good.
DR. HANSON: I was born in Georgia. Both parents were school teachers and lived in the country. We lived on a farm, but both my parents taught school and as a youngster they taught me at home. So I started school in the third grade at age seven. A little bit out of my age group, and I was out of my age group for about 30 years, but that didn’t seem to make any difference.
MR. LARSON: Fine. What city?
DR. HANSON: Smyrna, Georgia, which is about 15 miles out of Atlanta.
MR. LARSON: Yes, I know the location.
DR. HANSON: I walked about two miles to school and home. I owned ten cows as a child and milked the cows each morning before going to school and then again after coming home from school. So I had a busy life as a youngster.
MR. LARSON: Yes, that kept you out of the usual adolescent diversions.
DR. HANSON: Yeah, very much so. Very much school. So I started school in the third grade. I went to summer school and skipped the fifth grade. Graduated from high school in three years and at age 14 applied to college and was a little too young to get in. So I had to work for a year before going to college. Then I went to the University of Georgia at the age 15. I decided I was going to be a civil engineer and studied civil engineering and physics and that sort of courses to start with and my first year at college I took a chemistry course and the professor must be the person that lured me into chemistry because I was crazy about the professor and the course. So after one year I changed over to chemistry as a major and graduated in three years with a B.S. degree in chemistry. At the end of that three years, or in the middle of that third year, which now was 1929, a Dr. Billings from the Eastman Kodak Company who went around interviewing students at various colleges came to the University of Georgia and I had an interview with him. He offered me a job for the summer with Eastman Kodak Company in Rochester, New York. So that summer after I graduated, I went up to Kodak and had a very fine experience working there that summer.
MR. LARSON: That must have been a real privilege meeting a famous pioneer in photography, Dr. Billings.
DR. HANSON: Well, he wasn’t that much of a pioneer in photography. He was in the personnel part of it.
MR. LARSON: Oh, I see.
DR. HANSON: It was Eastman who was the name of the pioneer who was so important in photography at the time. And Eastman I had heard of even then. But I didn’t get to meet Mr. Eastman. At that time, Mr. Eastman was in his 70’s and I was a lowly student down in the laboratory, and I didn’t meet him. I’ll say more about that a little bit later. But one of the things I did that summer was to learn to blow glass. I made a lot of equipment out of glass in the laboratory there and I spent practically all of my noon lunch hours blowing glass because I enjoyed it so much, which I used a great deal in my graduate work later on.
MR. LARSON: If someone doesn’t have the skill of glass blowing in chemical research, he is severely handicapped.
DR. HANSON: He is severely handicapped, but probably not anymore, but in those days that was the case anyway. Well, after that I went back to Georgia, for two years and got my master’s degree in chemistry. While there I applied for a fellowship at ten colleges all over the United States. I picked out the big colleges and applied to ten of them. This was now 1932, and I didn’t get a fellowship anywhere. So I decided I would go to Berkeley because I had studied Louis and Randall, the text book of thermodynamics, the famous textbook. I knew those two names so I went to Berkeley.
MR. LARSON: As a matter of fact, I still have, I think, my Louis and Randall thermodynamics text, published first in 1924, or something like that.
DR. HANSON: I do too. I have mine too. Well, the day I left Smyrna, Georgia, to drive with a bunch of friends to California, I got a letter from the University of California saying that they were all full, please don’t come. I put that letter in my pocket and I went right on anyway. When I got out there they asked me if I received that letter, this was one time I did tell a lie. I said, “No, I hadn’t received the letter.” They said, “Well, since you are here, you might as well stay.” So I stayed. (laughter)
MR. LARSON: That is a remarkable story.
DR. HANSON: It is a true story.
MR. LARSON: I should mention at this time that you were in very good company because Linus Pauling had a similar situation and he applied for graduate work at the University of California and he was also turned down.
DR. HANSON: Is that right?
MR. LARSON: So you are in very good company.
DR. HANSON: So the first year, I went to work for Randall and I didn’t get to see much of him. He was very busy writing books still and I didn’t see much of him. The second year, I worked for G.N. Louis, which was very fortunate because he was a wonderful person to work with and for. He was of course the dean of the college and the dean of chemistry almost at that time. That was a very wonderful experience. And in 1934, two years later, I got my Ph.D. degree. At Berkeley, the graduation is held pretty early, in fact in May. Most colleges are later than that, but my birthday was, is the 28th of May, and they had the graduation the 25th or 26th, and I was still 21. So I can say I got my Ph.D. when I was 21 years old.
MR. LARSON: That is really remarkable. It should serve as some sort of record for getting a Ph.D.
DR. HANSON: Almost, almost. Of course I was 22 a couple of days later, but I was 21 when I got the degree. So I wrote to Kodak, I said I’ve got my Ph.D. degree now. I’m ready to come to work. I had a letter back from Kodak saying sorry we don’t have any jobs. This was 1934.
MR. LARSON: Yes, well that was a time in our history where jobs for both graduate and undergraduate students were almost non-existent.
DR. HANSON: Almost non-existent. That was the depth of the Depression. Well I waited a week and I wrote back to Kodak and I said I am very anxious to work at Kodak and they wrote back and said they don’t have any jobs. So, I waited another couple of weeks and I wrote them saying I haven’t applied anywhere else, I want to work at Kodak and I certainly do want a job. About a week later, I got a letter saying come to Rochester for interview, be prepared to stay. And so I went to Rochester in July of 1934 and have been there ever since.
MR. LARSON: That’s a remarkable story. Shows that persistence pays off.
DR. HANSON: Persistence pays off. I have given advice to two or three college students that persistence pays off and in a couple of cases it did for them too. So it’s worthwhile sometimes anyway. I started in the photo micrography department which was studying some miscellaneous subjects, but very shortly I moved over into color photography. That subject really attracted my attention in my life and that is where I spent most of my life from 1935 on in color photography. Can we cut a minute?
[Break in video]
DR. HANSON: A little bit about photography, just a, what it’s all about, or the history, how it came about.
MR. LARSON: Yes, well that background would be very helpful.
DR. HANSON: Actually, we go back all the way to Leonardo Da Vinci, who dealt with the camera obscura , which was the box for making images. Of course you have to start with the image and recording it is what photography is.
MR. LARSON: Oh, yes.
DR. HANSON: It was as far back as 1750, that a chemist named [Johann Heinrich] Schultz learned that silver salts were sensitive to light and then a little bit later it was found out that the light effect on the silver salt was to turn it to silver, and then every ten or 15 years, some new knowledge about silver salts developed. Other materials are light sensitive and in fact the first photograph that was called a photograph was made by bitumen , made by [Joseph Nicephore] Niepce in France that was an organic material that hardened by light. But still it was very shortly after that that silver salts came back into the picture, and in 1939, [Louis] Daguerre worked out a process using silver on a copper plate and developing it with vapors of iodine and the Daguerreotypes became important, and that was really the first photographic process.
MR. LARSON: I think you may have made a typographical error. You said 1939. You meant…
DR. HANSON: I mean 1839. I certainly did. Ok, that is right.
MR. LARSON: Which of course was a fantastic development.
DR. HANSON: That was quite a development and it had a lot of commercial use. I mean the Daguerreotypes these days are museum pieces. But there are quite a lot of them around, but it had a lot of commercial use.
MR. LARSON: The National Portrait Gallery has quite a line, a collection of the Daguerreotypes.
DR. HANSON: Yes, but silver salts in carriers rather than just on a metal plate in collodion , which had to be a wet plate process. You had to sensitize the collodion with the silver salt and never let it dry. So you had to do this in the dark end of the camera and then take the picture and develop it right then. So that was bulky. Finally, about 1870, silver halide in gelatin appeared to be a very sensible light sensitive material. At that time, it wasn’t very light sensitive, but it was sensitive enough that it began to be used, which brings me to George Eastman. George Eastman was a bank clerk in Rochester, New York, and he was interested in photography himself and he set out to make photographic materials which he himself would use, and decided that he would go into the business. He started in a very small way, still working as a bank clerk, but trying to make photographic plates out of silver bromide coated on glass. He was quite successful in 1880. He went into business and began to sell these plates. In 1882, he began to have complaints from a lot of customers that they felt the plates that they had were insensitive. He ran thousands of experiments and couldn’t find the trouble. He was buying gelatin from England and he and a friend went to England to just find out what they could find out. They did find that one particular batch of gelatin that they had bought was causing the trouble. There was something wrong with it and it destroyed the sensitivity of the plates. He replaced any plate that anybody had ever purchased. That was the way he did business right from the beginning. He replaced every plate that had ever been purchased and established his reputation that way. In 1886, he hired a chemist to do research. It was probably very nearly the first research in industry in the United States.
MR. LARSON: It must have been.
DR. HANSON: And he, it was very close to the first. And he hired this chemist to work out a film base so that they wouldn’t have to use glass plates. To use a flexible film and it would be lighter and more convenient.
MR. LARSON: Before that time, there had been no flexible films?
DR. HANSON: There had been the use of paper.
MR. LARSON: Oh, yes.
DR. HANSON: It had been coated on paper.
MR. LARSON: Oh, yes.
DR. HANSON: And then he went through a period of stripping plastic on paper. Then he worked out the clear plastic that did the job. So then by 1891, when [Thomas] Edison invented the motion picture, Mr. Eastman had the clear film and was ready to work with Edison on the motion picture films. He was right there and ready to work on the motion picture films as soon as Edison wanted it.
MR. LARSON: It would have been very difficult to invent the motion pictures using glass plates.
DR. HANSON: Yes, it would. And Mr. Eastman asked Edison, “What size should the film be?” And Mr. Edison said, “Oh, about that wide.” And that is how 35 millimeter film was developed.
MR. LARSON: That’s amazing.
DR. HANSON: Yes, it is. In 1895, x-rays were observed. In 1896, Mr. Eastman had a film ready to record x-rays. That just shows how alert he was and how he was staying in touch with the scientific world and working out applications of photography for whatever there should be.
MR. LARSON: That is an amazing story in science that this one invention and development just paved the way for x-ray applications.
DR. HANSON: Just paved the way for x-rays, that’s right. That’s right. Now another aspect of his character, the x-ray film, the motion picture film, and the film base that he had worked out was nitrate, which is very flammable. So he immediately set out to work out a more stable film base. By 1908, he had worked out safety film; this chemist had worked out safety film. Now, he tried to get states to pass laws that they couldn’t use nitrate, that they would only use the safety film. The safety film didn’t have the same quality that the nitrate film did, but nobody was interested and motion picture film was on nitrate until about 1948.
MR. LARSON: It persisted that long, despite of the danger.
DR. HANSON: It persisted that long. X-ray film was on nitrate until about 1929. There was a major fire in Cleveland of nitrate film and after that x-ray film was put on acetate film instead of nitrate. Now, I’m sort of jumping a head a little. In 1923, that company first marketed amateur movie film in the 16 millimeter form. Now that was on acetate film and even when I joined the company ten to 12 years later, we were not permitted to slit any film, any nitrate to the 16 millimeter size. I mean, Mr. Eastman said there would be absolutely no inflammable nitrate film in the 16 millimeter size which goes into people’s homes. So he was very safety conscious from the beginning. He was a very conscious person of safety.
MR. LARSON: I have never heard that story before. We all know of course that the nitrate base is also in a form of gunpowder.
DR. HANSON: Yes, that’s right.
MR. LARSON: It’s terribly dangerous. I believe that Cleveland fire killed…
DR. HANSON: I don’t know the story of it, but some people were killed, yes.
MR. LARSON: I think it was 25 people. That is a very interesting story about how that developed. I’ve never seen that before. It was very interesting.
DR. HANSON: Now that is just the kind of person he was. Now in 1911, he visited the chemical industry in Germany and some of the leaders of that industry asked, “Well, now tell me about your research laboratory.” And he says, “We do a lot of research in the plant,” and they did. But these folks said, “Don’t you have a research laboratory that does fundamental research?” And he said, “What we think we do is fundamental research, but what we do is done all in the plant.” Well that got him thinking and wondering about a research laboratory. And so he asked some of the people in Germany, he said, “If I were going to set up a research laboratory, who should I get to head it?” There was almost unanimous opinion, it should be Dr. C.E. Kenneth Mees, who was in England. He was a managing director of Wratten and Wainwright. He had been an early pioneer in studying this science of photography and was a business man and a scientist. And so Mr. Eastman went over to interview Dr. Mees. By the way he had met Dr. Mees a few years earlier when Dr. Mees visited the United States. But anyways, he went in and asked Dr. Mees if he’d come and head a research laboratory in Rochester and Dr. Mees said he had a commitment of Wratton and Wainwright. So Mr. Eastman bought the company Wratton and Wainwright and Dr. Mees moved to Rochester.
MR. LARSON: That’s amazing story. In order to get the man, he had to buy the company.
DR. HANSON: Now, he didn’t go around Mees’ back to do this. Mees and he sort of worked out this deal that he should buy the company, but he did buy the company and Dr. Mees came to Rochester, in 1912. One other thing about Mr. Eastman, I mean, he and the company is just worth knowing about. In 1918, during World War I, we had been getting a lot of, chemicals, organic chemicals, not just the Kodak Company, but the whole country, got organic chemicals from Germany.
MR. LARSON: Oh, yes.
DR. HANSON: And that source was cut out. So in 1917 I guess it was. Mr. Eastman set up a laboratory to manufacture organic chemicals and Eastman Organic Chemicals is still available to colleges and people that need them today.
MR. LARSON: Oh, yes. Of course that, in chemical research we always turn to Eastman Fine Chemicals for a supply of chemicals. Almost every research laboratory in the country did that.
DR. HANSON: Yes, well that started in 1917, during the war.
MR. LARSON: That’s very interesting as to the origins of that.
DR. HANSON: At the end of the war, the Eastman Kodak Company rebated to the government all of the profits that they had made out of government contracts during the war, World War I. Now, that’s another characteristic of the company.
MR. LARSON: That’s a very interesting story and one which I had never heard before.
DR. HANSON: In the Second World War, V-mail was used, I’m jumping way ahead, but still this is part of the story. V-mail was worked out for cutting down the loads of ships, I guess there weren’t airplanes carrying around mail in those days, and all the letters to soldiers were microfilmed and sent on film and were reprinted at the site. This was worked out in England and then used first by the English Army and then by the American Army, but it was worked out in England. By the end of World War II, all of the profits made of that operation were given back to the English government.
MR. LARSON: Oh, yes.
DR. HANSON: So it really was, he as an outstanding man, and the company that he developed, you can see that I am very enthusiastic about it.
MR. LARSON: That’s a very interesting, valuable aspect.
DR. HANSON: Well now, my life was built around color photography. So, let’s get on to color photography.
MR. LARSON: Well fine, ‘cause that of course, that development is one of the most fascinating scientific and technological advances of our country.
DR. HANSON: It is a very interesting one and has been very successful. You might say it started back in 1861. Clark Maxwell in England demonstrated that color pictures could be made by photographing a subject with red light, and green light, and with blue light and then projecting pictures through a red filter, and a green filter, and a blue filter, superposed and that those three would make a full color picture. Very soon after that a fella named [Louis] du Hauron in France, showed that you could make a color picture by superimposing, not projecting three, but by superimposing three pigments which were yellow, magenta, and cyan. If you took a picture with blue light and you printed it with yellow pigment, took a picture with a green light and printed it with magenta pigment and took a picture with red light and printed it with cyan pigment and overlaid them, then you would have a color picture.
MR. LARSON: We use, it’s a compliment.
DR. HANSON: Yes, compliment. Yellow, magenta and cyan, are the compliment to red, green and blue. Now there wasn’t any technique for doing that photographically in those days. Painting and lithographic printing used the subtractive, the yellow, magenta, and cyan paints or pigments and then for many, many years there were a lot of prints made in three colors, but not photography. Now the prints that were done were called red, blue and yellow. Now, the yellow was yellow, the red was a pinkish red. They really wanted magenta, but there weren’t any pigments that were magenta, and they were sort of red. And the blue, they wanted blue-green, but there weren’t any pigments that were really blue-green, they were sort of blue, so they were called red, blue and yellow. And those are the subtractive colors that most people know about. Those terms that I use in explaining the very important invention that I made in 1943, but I’ll get to that way down the road of course. Well anyway, so the basic principles of additive and subtractive photography were known back in 1960, 1860. I keep using 19, it’s 1860.
MR. LARSON: That’s amazing that the fundamentals were known so early, but there was no way to take advantage of it.
DR. HANSON: No way to take advantage of it. And the need, the desire for color photography has been there forever. Photography just happened to be black and white. I was talking with a young lady who is writing a history of color, recently. She was saying, well, the 1920’s, the 1930’s, the climate was right. The culture was ready for color photography and I insisted that the culture was ready 1000 years ago for color; it’s just that the technology was limiting. And this whole thing has been technology limiting right up until now almost.
MR. LARSON: Yes. Incidentally, to divert for just a moment, I recently saw a book with color photographs in it of the early work in Russia on color photography, back even before 1920 and in the 1920’s. A very obscure book, but very interesting.
DR. HANSON: People have been trying to work out color photography since it was, since the basic ideas were there in the 1860’s. People have been trying. The additive process which Maxwell demonstrated first, was worked out in practice and by 1907, or ’08, the Lumiere Autochrome Process which was colored starch grains, red, green and blue were coded on the back of a plate, or on a plate, and then the emulsion was coded on that. Take a picture with that, develop it to a negative, dissolve out the negative and convert it to a positive, and project it and through the red, green, and blue starch filters you’ve got the picture just of the sort that Maxwell had illustrated. That was on the market. Now it was very slow and not very sharp, but it was color photography and it was clearly used and important.
MR. LARSON: Essentially those starch grains that acted as micro…
DR. HANSON: As micro light filters.
MR. LARSON: …filters.
DR. HANSON: That’s right. Then later in the ’20’s, maybe the late teens and the ‘20’s, [Louis] Dufay in France came out with a method of making screens, I mean lines of red, green and blue filters, so Dufaycolor used the organized lines rather than the random starch grains. Finlaycolor was a different method of making the screen plates. So there were those additive color processes in commercial use starting in 1907. In 1905, Schinzel, an Austrian who later came to Kodak for a few months in the late ’30’s, worked out the idea of having several layers of sensitive emulsion, a red, green and a blue sensitive emulsion on top of each other on the same film base. That idea wasn’t practical at the time. Then in 1912, Fischer in Germany had the idea of using color development reaction. There are certain developers that develop the silver halide to silver that will react with a coupler to form a dye. And he was able to find couplers that would give a yellow, a magenta, and a cyan dye. So he worked out the color developing process for making color pictures, but he had no way of putting the color in one layer, another color in another layer, and the other color in another layer. So he wasn’t successful in doing the job. This was 1912. Well now in 1912, when Dr. Mees came to the Kodak research laboratory, he knew that color photography was really the objective of photography, and the whole laboratory though it wasn’t devoted to that. The idea came along that it might be useful to develop the color process was investigated pretty thoroughly. There was two or three process that almost made it during the teens. Dr. [Herbert] Kalmus of Technicolor in the late teens set out to make color motion pictures. And I’m not going to go through the details of his process, but he started as most everybody did, with an additive process and if you don’t get the pictures properly superimposed, you get bad color fringes. He immediately found that and set out to make subtractive processes. He did work out a subtractive process and they made two or three, Technicolor made a couple of pictures during the ‘20’s, two color. You can take some shortcuts and make a two color process which gives some colors pretty good. It won’t reproduce all colors, but it’s a color picture, that’s a color picture anyway. They made a couple of movies two color, but they kept working on the three color process. In 1932, I’m sort of tracing them all the way up, 1932; they came out with their first three color movie, which was just…
MR. LARSON: Those movie films that were made before that were done with the two color process.
DR. HANSON: Two color, that’s right. By 1928, Kodak had gotten patents from others and had worked out a motion picture film that was three color, the lenticular film. Now that again was additive without fringes and a very unusual method of making color. The film base was lenticulated so there were lenticular lenses and there were stripes of filters, a red filter, a green filter, and a blue filter, on the lens, and those three colors would be focused by the lenticular lenses into the film and that was developed into a negative, the silver taken out and reverted to a positive and projected back through the filters, and you got a very good color picture that way. It was a very slow; it took a lot of light because the filters absorbed a lot. Took a lot of light in the projector because the filters absorbed it coming back, but anyway Kodak put that on the market in 1928. That was the beginning of color film for Kodak, but now let’s go back a little bit because the real color photography came along and was developed by a couple of musicians named [Leopold] Mannes and [Leopold] Godowsky. Their story is really something. They should be the ones sitting here instead of me, except they are both gone.
MR. LARSON: That’s, I’ve heard just a little bit about that, but I’m anxious to hear what you have to say about that.
DR. HANSON: Well they were friends in high school; both musicians and both parents were well known musicians. They got interested in color photography, and began to study it and read about it. They too started with an additive process. An additive processes had color fringes, so they weren’t going to have three or four different lenses taking the pictures. They were going to take the pictures through one lens and divide it with a mirror so there wouldn’t be any color fringes. They put on a big show in New York City, about 1917 or 1918, but they were projecting through two different lenses and they projected out of sync and they had bad color fringes. So they said no more additive color photography. We’re going to work on subtractive color photography.
MR. LARSON: But they had started…
DR. HANSON: They had started as early as the late teens.
MR. LARSON: That I had no idea.
DR. HANSON: They were working in their parents basements in New York and R.W. Woods of Johns Hopkins, a physicist, knew Dr. Mees and he knew them. And he introduced the two to Dr. Mees. Dr. Mees went down to New York and saw their work, which was very rudimentary, they weren’t getting very far, but anyway, he kept in touch with them and decided that he, the Kodak Laboratories would supply them with materials that they needed, plate coatings and various chemicals were sent to them from Kodak, at some low price, I’m sure. Finally, they were beginning to make some progress and showing some pictures that looked like maybe they had a technique of making color photography work. Then in the late ‘20’s Leslie Broker, an organic chemist in the Kodak research Laboratories who was working on sensitizing dyes to make the silver halide grain sensitive to red green and even into the infrared…
MR. LARSON: So called panchromatic…
DR. HANSON: So called panchromatic. He worked out some sensitizing dyes that could be put into emulsion and it would not wander from one layer to the next. Up until that time all the sensitizing dyes would wander so you couldn’t really coat a red sensitive, a green sensitive and then an unsensitized blue sensitive on top of each other and have them keep their sensitivities separate because the sensitivities would wander. But he worked out sensitizing dyes that would stay put and as soon as this happened, Dr. Mees, who was really a very intelligent guy, realized, “Ok, color photography can be made to work using the multilayer system now.” He invited Mannes and Godowsky to come to Rochester and work at the Kodak Research Laboratories. So they came in 1930 to Rochester and went to work. Now of course they had much of the research laboratory available to them and what could be done in the plant available to them. They asked for coatings made in the plant of two or three layers of emulsion and the plant would say they can’t make them that sort of thing. And they would insist and the plant would try and they would make multilayer coatings. They were musicians; they were talented; they worked in the dark room and they timed their experiments by whistling or humming classical music. They knew the timing of the classical music and they timed their experiments by whistling classical music. Now that is a true story. I’ve heard them, I’ve heard them.
MR. LARSON: That is an amazing story. That’s a new method of precise determination of a timed lab.
DR. HANSON: Yes, it is. Yes, it is. A lot of the people in the laboratories spoke of those musicians because they did practice their music, they gave symphonies; they took part in the musical parts of the city, but in the laboratory, they were imaginative, they weren’t scientists. They were imaginative and darn good experimenters and persistent. They tell a story that about 1932, ’33, when the Depression was really getting bad and people were getting laid off and certainly there was no expansion in research and business was bad. They were afraid that maybe they were going to be let go. So they sat down and wrote out…
[Break in video]
DR. HANSON: As I said, in the Depression, people were being let go, Mannes and Godowsky were afraid that they weren’t going to be kept in the research laboratory. So they decided to sit down and write out every step of a color process that they knew for certain how to make work.
MR. LARSON: Oh yes.
DR. HANSON: So they wrote down all of these steps and began to put them together and see if they could come out with a color process and sure enough they did. It was very complicated and only a couple of musicians would come out with something this complicated I think, but it worked. They made two color pictures that really were quite exciting. Dr. Mees looked at them and said, “We’ll go on the market with this.” And they said, “No, let’s go now for the three color process.” He said, “No, we’ll go on the market with this.” So the company started toward the market with the two color process, but they…
MR. LARSON: I had never heard of that.
DR. HANSON: Yeah, but they scurried around and put together the three color process and made it work and they did that fast enough so that the two color process never went on the market and the three color process did. In 1935, Kodachrome 16 millimeter film was put on the market and the process took, it had a something like 28 to 30 steps all of them in timing and temperature control. It took two and a half hours. It was a very complicated process. Their major contribution, the one part of it that they contributed, that wasn’t an idea from a lot of other people was depth bleach that was the way you would get the colors in the right layer and in only one layer. The sensitizing dyes in each layer stayed there, that was all right. The coupler developers which Fischer had developed back in 1912, they used and the dyes didn’t wander, but the couplers did, but they worked that out. The way they worked that out is they developed the cyan color in all three layers, first, after developing the negative image.
MR. LARSON: Yeah.
DR. HANSON: Then the rest of the silver halide they developed the cyan color in all three layers and then they would dry the film and then they had a differential depth bleach that would start bleaching slowly from the top and they could control exactly where it would stop bleaching by a stop bath. That was the secret. That was their invention that made this possible. So they would bleach out the top two layers, bleach the dye out and convert the silver back to silver halide and then wash that out. Ok, then they would develop the top two layers to magenta dye and dry the film and then slowly penetrating depth bleach would bleach out the magenta dye from the top, convert that silver back to silver halide, wash that out, and then develop that to a yellow. And that is how they got the cyan in one layer, the magenta in the next layer, and the yellow in the next layer.
MR. LARSON: I should think that almost anybody would know you certainly can’t control the diffusion of anything to a thousandth or a ten thousandth of an inch.
DR. HANSON: Exactly. You certainly would.
MR. LARSON: Anybody who knows anything would know better than to try that.
DR. HANSON: Exactly, but that’s what happened and it worked.
MR. LARSON: Remarkable.
DR. HANSON: It was remarkable. In 1935, Kodachrome 16 millimeter film was put on the market. Now at that time, Dr. Mees was head of the research laboratory; he made a bet with Mr. Lovejoy, who was the chairman of the company that within 5 years color film would be outselling the black and white film. Three years later, Mr. Lovejoy paid off that bet because within three years color film had overtaken the black and white. That just showed that everybody was ready for color when it was ready.
MR. LARSON: I can still remember the first color movie film that I saw, which happened to be one, someone had taken on an expedition of the South Seas and everyplace that was showing, I think it was on 16 millimeter, the place was sold out.
DR. HANSON: Absolutely. Well, this was the birth of modern day color photography, up until then there had been some tries and there were some commercial applications, but this was the birth of modern-day color photography. And as of now, practically all of the color processes in use by all manufacturers and by all people is based on this color development reaction, different aspects of it. But this type of chemistry is used now in practically all color photography.
MR. LARSON: There have been no real, big fundamental change.
DR. HANSON: There has been no fundamental change, two or three changes have made all the difference in the world in quality and so forth, but they really aren’t that fundamental. That is one thing that interests me about an invention, I mean an invention maybe a little improvement on something, but from a usefulness point of view, that may be tremendous. An invention maybe a completely new thought, but when you get through with it, it has no application. It doesn’t make any difference.
MR. LARSON: That’s right. That’s very true. That’s a concept that sometimes is very difficult to get across. Some scientific triumphs at least in the period of time for ten to twenty years might have no…
DR. HANSON: Might have no…
MR. LARSON: …difference.
DR. HANSON: …make no difference and yet the idea and the thought leading up to it is just a big a jump.
MR. LARSON: Right. Well, very good.
DR. HANSON: This is when I came into the picture. That film was on the market and I was asked to come and work on 35 millimeter, 35 for the Leica and Retina cameras, for amateur slides. So I entered that program in 1936. When I went into that I was asked to also, sort of as a side line, to write a series of articles on the history of the science of photography, which fortunately forced me to study all of the literature in the science of photography which I had done before. That was a good thing. Somebody asked me to do that, I did it and it really was a very important thing because it forced me to learn what was known about photography. So I became interested in the science and I worked in the science of it as well as the practice of the color photography. So we went to work to apply this complicated process to 35 millimeter for the amateur. That took a lot of detail doing, but no major changes were made. We also, the group that I was in, had the responsibility of looking ahead and planning to adapt this process to the motion picture industry. Now Technicolor had a patent on the multilayer films. Mr. Trolland of Technicolor in 1917, 1918, applied for a patent on multilayer sensitivities and that patent was granted in 1931. So it stayed enforced until 1948. Kodak of course had to have a license under that patent and we could not have manufactured and sell motion picture and color film using that patent to anybody. But we still we went right to work on trying to apply the Kodachrome process to the motion picture industry, through Technicolor and eventually to others. So that was our job. Now a part of that job, part of the use of color film in the motion picture field is you have a camera negative, you take the picture, or with camera film, you take the picture, you make hundreds of prints to go around into the theaters. You have to have some intermediate stages to put in dissolves and fades and embellishments, that sort of thing. So you have to make copy after copy after copy after copy. Making a copy of Kodachrome to another Kodachrome you don’t get such a good picture. Now, a Kodachrome slide is a beautiful picture, but you make a copy of it, it’s not so good. You make a copy of that and it’s pretty poor. So one of my objectives right from the beginning was to learn how you make copies of color pictures. I thought that, I worked that for 5 or 6 years and I’ll come to that later on. While we worked out the amateur film, we were also working on applying it to motion picture professional and working on different techniques of making copies and everything we could think of we would try. As we went to market with Kodachrome 35 millimeter film for slides, we had production charts on the wall and we had them listed as the Leica Program, now the Leica was an important 35 millimeter camera at the time. In fact, 35 millimeter amateur cameras were relatively new at that time. Most amateur photography was with big roll film cameras and the 35 millimeter camera had just come into use. Well, we had listed on the board the Leica Program. Well, some management people came down and saw that and changed it to the Retina Program which is the Kodak 35 millimeter camera. That is just a little aside that was amusing there. But, ok, so, we got the 35 millimeter on the market and immediately began to try to improve things. The research was never cut back. Research in color photography was always increased. We knew that color was wanted across the board so as we can learn to do it, we’ll do it. But first of all we had to simplify that process. That process was 30 steps, two and a half hours, was too complicated. So a couple of inventions were made so that the process was simplified a great deal by 1938. Instead of having the depth penetrating bleach, it was found possible that after you develop the film to a negative, you could expose with a red light the residual emulsion that was left and expose only the red sensitive layer then you could develop that in the cyan color developer then you could expose with blue light and expose only the blue sensitive layer because there was a yellow sensitive layer which kept the blue light from getting into the middle and develop that with the yellow developer and then fog, or expose with green light the middle layer develop that with magenta so that you have the three color developers that you did by exposure and not the depth bleach. It was a much simpler process. There weren’t nearly so many steps. And it was much easier to control. So the process was converted to that method in 1938. Now there had been a number of minor changes in timing and it was cut down to 18 minutes, the temperature has been raised, and a lot of things have been improved since then, but basically the process is the same now as it was in 1938.
MR. LARSON: Well, that is a wonderful explanation of these very fundamental developments that have lasted to…
DR. HANSON: They have lasted to this day. Now we immediately set out to apply this process to sheet film for commercial use. We went up to, I guess, 14 by 17 sheets was the biggest that we did, but we were successful in developing, adapting a machine that would operate this process and adapting the Kodachrome process to commercial use and Kodachrome sheet film was very important in the commercial field and advertising field for a number of years. Just as that was beginning, Bradford Washburn who was, oh let’s see, what was he? He was in charge of the Harvard School of Geographic Exploration, and later became the head of the Boston Museum of Science. He was a photographer and he wanted to take a lot of pictures of Mount Everest and all over Alaska, not Everest, I’m mean McKinley, sorry, and all through Alaska. One of the members of the research laboratory at Rochester got him some Kodachrome sheet film and he took a lot of pictures. He was told, now this is color film, you don’t use a filter because that is just for black and white film for effects. Color film you don’t use a filter. Well actually, he was using film that was balanced for artificial light and he was taking it in daylight. He should have been using a filter actually. (Laughter) So the film came back to us for processing and here the first batch of it processed and it was obvious what had happened. So I was given the job of completely working out a new process to use to try to get that improperly exposed film to come out looking right. I spent weeks working on a process for that, but got one that worked all right. So we got some excellent aerial shots that Bradford had taken on the wrong kind of film.
MR. LARSON: I think all of us at some point put the daylight film or artificial film, made a mistake or forgotten; you know what the effect is.
DR. HANSON: Yes, well it was possible to work out a special process to handle that. So that was done. We immediately set out to adapt the Kodachrome process to roll film. Now roll film was the standard film that all amateurs used, and all amateurs wanted prints and Kodachrome to this point only made slides. So we set out to adapt it to roll film and to paper and to make prints from the roll film to the paper. Now here again the problem with making a print from a Kodachrome was with us. Techniques called masking had been worked out and helped. I’m not going to go into all of the details of how masking works, but anyway a mask, a negative image, in contact with a positive image, when you print it. You can devise a mask that will give an improved quality. So…
MR. LARSON: Commercial people in printing use that a lot.
DR. HANSON: People in commercial printing use to use masks all the time. I don’t mean mask around the edges of the picture, you know, a negative image on a positive image. We devised a method of adding a mask to the Kodachrome roll film, a silver image mask, and that added about 15 steps to the process. That put it back about as complicated as it had been to start with. But it worked almost and the quality of the pictures was improved by it. Another problem, the Kodachrome coated on paper gave model. The Kodachrome is the reversal process. You use everything that is there. You develop the negative and dissolve it away and then you use all that is left in the emulsion to make the picture. Paper had little irregularities and so there was model. For two years we worked on that problem and I used to go to meetings in the plant where they made paper and they made coatings and every two weeks we had a meeting and somebody would report that model had been improved. After two years, the model was essentially the same as it was to start with.
MR. LARSON: One of those intractable problems.
DR. HANSON: One of those intractable problems, but I went back and reviewed all of the minutes of the meetings later and every meeting it was reported improved, but it hadn’t changed a darn bit. Well anyway, it probably was fairly acceptable and we were already to go on the market with this very complicated roll film process and this paper with model when the Kodacolor process came along. I guess I say we were sort of saved from ourselves. Now let me tell you about the Kodacolor process. As I have said Kodachrome, you go through the three color developers and each one of them puts one color in. Earlier couplers had been invented which you could put the coupler itself in the emulsion and it would stay in that layer. You could put a cyan-forming coupler in the red sensitive layer and you could put a magenta-forming coupler in the green sensitive layer and a yellow-forming coupler in the blue sensitive layer. Now making such couplers was complicated chemistry and designing them was sort of complicated. Kodak had been trying to design such couplers. In fact, people had been trying to design such couplers since Fisher back in 1912. In the middle ‘30’s, Willmans at Agfa in Germany did design such couplers and Agfa came out with a color negative process, not a reversal process that made the color negative in the late 1930’s. About the same time, Kodak was working on couplers that you could put in the emulsion. And Vitum and Jelly a couple of people in the research laboratory came up with the idea that you could make a coupler with a ballast, a big molecule on it, which you could dissolve in an oil, disperse the oil in the gelatin emulsion and that the coupler would react. The developer would go into that oil and react to form the dye and sure enough that worked. The couplers that Agfa had worked out had a big ballast too. They also had a solubilizing group so that it would dissolve right in the emulsion rather than being put into oil. That turned out to be a surfactant. Just by nature that was a surfactant, it made those things very difficult to manage. So in the long run by chance the protected coupler process dissolved in the oil had proved to be the process that all of the companies use. That is just one of those things that worked out that way.
MR. LARSON: Oh, yes.
DR. HANSON: That was invented, worked out about 1939, 1940, and just before we were ready to go on the market with Kodachrome roll film and paper, this process came along and so the whole program I had been working on night and day for two years, was scratched. Other people had been working on the Kodacolor so that moved along very fast and Kodacolor roll film was put on the market in 1941. In the meantime, I went back to working on Kodachrome. I was at that time, mostly a Kodachrome person, not Kodacolor, and I went back to working on Kodachrome for application in the motion picture industry and though we couldn’t sell it generally, we could sell it to Technicolor so we worked out a Kodachrome process that, film with the characteristics properly adapted to the motion picture use and Technicolor began to use that film in 1942, I think, and used that film for a little while and made a few pictures with it. We also decided to begin to make prints from the Kodachrome slides. By now Kodachrome slides had gotten to be pretty popular. There were a lot of them out there. So we worked out instead of a Kodachrome process on paper, we worked out a Kodachrome on white pigmented support, which was smooth and you could use the reversal process without the model. So we put on the market there in the research laboratory the mini color prints which were made from Kodachrome slides and we did the production of mini color prints for many years. And that process had some unique features. It took a little bit to work out a process of that sort but it was no big change in procedure, or in science. All of this time, the problem with making these prints and making the quality with masking, or without masking was in my mind and everything that came to mind was being tried. Finally, in 1943, lying in bed, I thought of an idea. Supposing that coupler, and this applied to Kodacolor, not Kodachrome, supposing that coupler, like the cyan coupler which is going to form a cyan dye, supposing that coupler itself is colored yellow or orange, when the cyan is formed the yellow or orange will be destroyed and so you have a cyan negative image, and a yellow or orange positive image and that orange, I will call it, will just cancel out the undesired blue and green absorption of the cyan dye, and so you will essentially have a perfect cyan dye. Now the magenta dyes absorb some blue, and are actually reddish rather than pure magenta. So that magenta color is going to be yellow and the yellow positive will just cancel that blue absorption of the magenta dye so that you essentially have a perfect magenta dye. Now already, yellow dyes don’t absorb green and red so essentially the yellow is perfect. So with colored couplers of this sort, you could make a copy that would be exactly like the original, or exactly the positive from a negative, but still you would have any of the color defects caused by the improper dyes. So…
MR. LARSON: That is a remarkable thought.
DR. HANSON: So, lying in bed I thought of that.
MR. LARSON: That is a very amazing sort of flash that you had.
DR. HANSON: It was a flash. I had been working on the problem and thinking about it for years, and reading about it, but that idea came lying in bed one night. I immediately went in the next morning and wrote a half a page invention report and went to one of the guys, Vitum who had helped invent the Kodacolor process, and I explained the idea. He says, “You know, I think I got a coupler on the shelf here that’s already yellow, maybe this will work that way,” and we tried it. And the very first try, it worked sort of. So we could see that the idea was working. Immediately, several of us got excited about it and began to follow up and try to make that work. One month later, I joined the Manhattan Project and left color photography for a couple of years. Right at that point when I had that idea, I left for two years. Let’s break now.
MR. LARSON: All right.
[Break in video]
DR. HANSON: I think I’ll sort of enter a diversion and talk a little about the science, basic science of photography. The light sensitivity and the development process. The photography is based on using a material that reacts to light. But that reaction has to be magnified a great deal. The development process in the photographic process amplifies the effective exposure by millions of times. Now a lot of materials are sensitive to light. But there are not many, in fact maybe none that can be, react to such a small quantity of light like silver halide and have that small quantity magnified in such a large amount. Now many materials have been investigated, polymers and all sorts of chemicals, but it turns out that silver halide is unique. This has been learned as we have gone along and people are still learning about it. But, way back, everything was empirical, making the silver halide grains, people tried things, they would find that they were more sensitive than the other. Then in the 1920’s Dr. Shepard in the Kodak Research Laboratories began to study gelatin and its effects on the grains that were made and it was found out that gelatin has some sulfur compounds in it. That cows eat mustards in the fields and that puts some sulfur compounds.
MR. LARSON: Oh yes.
DR. HANSON: And these sulfur compounds sensitize the silver halide grains and make them much more sensitive than they would be otherwise. They also can go too far and fog the silver halide grains. And that was one of the problems that George Eastman had back in 1902, 1882, ‘83, when his plates were going bad, it was a bad batch of gelatin.
MR. LARSON: Oh yes.
DR. HANSON: But it was in the 1920’s that that became understood, the role of gelatin and the role of sulfur in sensitizing the silver halide emulsion.
MR. LARSON: That poses a real problem in control by being dependent on how much your cows eat of the mustard.
DR. HANSON: Exactly. You know it was a long time before it was possible to thoroughly purify the gelatin and eliminate those things and then add the amount of the sulfur compounds that you want add. Of course, that’s the way its done now, but that is only a recent development that that has happened. Then in the 1930’s, people began to study the mechanism of the formation of the image. Webb at Kodak, Ernie Mott, Bristol England, later, Mitchell, John Mitchell, also in England who moved to the University of Virginia, studied the mechanism of the formation of the image and how one or two photons could make a stable speck in the mechanism of silver ions moving through the crystal and then trapping electrons and then that sort of making a speck that the next silver ion released by light would move to the next speck. That sort of understanding of the sort of electronic nature of the silver halide crystal and its behavior began to clarify the process and made it possible by scientific means to work out means of improving the speed and making those specks more stable, making them more sensitive to the development, the mechanism of how the developer could act on that speck. I mean that developing agent has to be a reducing agent that will reduce the whole silver halide grain eventually, but making it reduce just the exposed grains with a very small speck and not the other ones is part of the, for a while, it was entirely empirical, but through the ‘30’s and ‘40’s, those things began to be studied very quantitatively so that as of now, speeds of the emulsion are in the thousands, when they were in the one’s and two’s back in those days. So all of those things are a very important part of the development of color photography, or any other photography. And many research laboratories, Agfa, the Japanese have made important contributions, but the Kodak Research Laboratory was sort of the center of the development of this science for many years. In 1936, a member of the Agfa research laboratories discovered gold sensitizing. You could sensitize emulsions with gold that increases, a little speck of gold, that increases the sensitivity by a factor of two or three times, which is very important. I can remember in the late 1930’s when Agfa came out with a motion picture film, this was black and white, which was faster than the Kodak film. You could also make faster films by having bigger grains and making it grainy, so having speed grain is the factor that’s important. They came out with a film that was less grainy than the Kodak film and was faster. Now there was pandemonium in the Kodak research laboratory.
MR. LARSON: Oh yes. I imagine that was a real emergency.
DR. HANSON: Everybody involved had to go to work on what was it that they were doing and how could we do as well or better. Within a short time, gold sensitizing was discovered independently in the Kodak research laboratory and used. Now, Agfa did not patent it.
MR. LARSON: They tried to keep it a secret.
DR. HANSON: They tried to keep it a secret, and Kodak later did patent it. Now, there were variations that were patent.
MR. LARSON: Oh sure.
DR. HANSON: But Kodak did patent it, but there was a lot of scurrying around in those days to learn how to sensitize emulsions that way. Now there have been a few other major contributions to emulsion technology that gives speed grain increase, so that as I say the speed has increased many times since 1930. That was an interesting activity. Now another part of speed of the emulsion is spectrosensitizing. Organic dyes are absorbed to the grains to make them sensitive to green, and red, and even infrared. Now the mechanism of the transfer of the energy from the, that’s absorbed from the dye into the grain has been a very important study and is a fascinating study. I mean, many dyes will not transfer that image. In fact, many dyes are desensitizing dyes. You put them in and they desensitize, but learning how to make one photon of absorbed energy from a dye transfer and give one atom of silver into grain took a lot of doing. And again, that study goes on in all of the research laboratories in photography. Well, let’s get back to sort of the chronology of the development of the various films.
MR. LARSON: That clarified a good deal of the history of the development of the science and technology of photography.
DR. HANSON: We were about 1941, ’42, no we were up to ’43 when I left. That’s right when I left. Well, during the war, the Kodacolor process which had gone on the market as roll film was adapted for the use in aerial photography. Now people in the Army had come to Dr. Mees at Kodak and said, “We have got to have Kodachrome for aerial photography. You got to teach us how to process it in a truck”, and Dr. Mees said, “There was absolutely no way that you could do Kodachrome that way.” He said, “We got this other process; we’d have to go to work real fast to work out a film using that process.” So Kodacolor aero later called Autochrome aero was worked out and was used during the war.
MR. LARSON: For aerial…
DR. HANSON: For aerial reconnaissance, yes. And also as part of that use, infrared sensitive film was worked out too. That gives false color. If one of the three colors is infrared sensitive then you get quite distorted colors and that becomes a camouflage detection film and that was used for camouflage detection.
MR. LARSON: Oh, yes.
DR. HANSON: Fairly successfully, yeah. Well, when I got back to Rochester in 1945, the Kodacolor aero film was in use and had been developed. Autochrome film which was that same process being applied to professional use, sheet film Autochrome was just about ready to go on the market. The colored couplers which I had thought of just before leaving, had been worked out and were just about ready to go in the product on the market. A lot of work had gone on there, designing the couplers themselves, having them have just the right color. I mean I talked about the cyan coupler being yellow or orange. Well it had to be exactly the right tinge of orange. And it had to have the right intensity. If it were too orange, it wouldn’t exactly match what we wanted it to match. All of those things had to be worked out. The reactivity of the couplers with the developers, all of those things had to be worked out too, but they had been worked out. A lot of work had gone on and it was just about ready to go on the market. I’m very pleased with that naturally. One other thing that had happened too, Kodachrome developers are toxic, I mean allergenic. If you get color developers on you, the ones that were classically known, you get a skin rash. Dr. Mees had decided that no way we would sell for anyone else to use the Kodachrome process or any other process using those developers. We have got to have a non-toxic developer, even for the military. So the chemist, Arnold Weisberger, had been working on making developers and he invented, or worked out the formula for a new color developer that was non-allergenic. And so just about the time I got back to Kodak, that was being worked into the system and in fact, it had been used in the aerial film. The Army use was the non-toxic developer. But let me talk about Arnold Weisberger a minute because he is a well-known chemist who came to Kodak in 1936. He had, he was from Germany and left Germany to go to England in the early ‘30’s, as a result of Hitler.
MR. LARSON: Oh, yes.
DR. HANSON: And he became one of the well-known chemists in the world. He wrote books and edited many books, but he came to Kodak and he began to work on compounds for color photography. So I met him in the middle ‘30’s. He remembers this story, which I should have told a little earlier, but I don’t remember this story, but he was making magenta couplers for us when we were working out the Kodachrome process for 35 millimeter film. The magenta coupler was a brown, powdery stuff, very impure chemical. He brought us over a sample of nice yellow, clean crystals. He had really made a batch of that coupler that was just as pure as could be. We tried it. He tells the story that he came over to find out what the result was. And so I said, “Arnold, you sit down right here.” I showed him the result and we got about 80 per cent dye with a pure compound as we had gotten, always gotten with the impure compound. (Laughter) And we found reasons for that, but that set back the purity of compounds for a long time, I’ll tell you.
MR. LARSON: That’s amazing how some of these things work just the opposite.
DR. HANSON: Just the opposite, yes. Well, of course by the time the compounds were put into the emulsion, not in the developer, they had to be very, very pure. So the purity of compounds did become very important, but that set it back for the Kodachrome process for quite a while. Well, gee, where was I? Well, as I said, the color couplers had been worked out and were in a film just about ready to go on the market in 1946, and in fact, in 1947, Autocolor seed film went on the market. That was a professional film using the color couplers, the first film using the color couplers. It used the non-toxic developer, it was for use by professionals and they were to make prints using the dye transfer process. Now Panmatrix film, a matrix film which you can expose with red, green and blue light, through the color negative, the Autocolor negative then make a dye transfer print. So commercial photography now had been simplified and prints could be made by professionals. At this time, we were still looking for new applications, looking for new science. I and my boss, Mr. Ralph Evans, were very interested in the science of color and applying that to color photography. We studied colorimatry, we decided to write a book on the principals of color photography, which we did in fact and was published in 1951 or ‘52, and began to work out all the theories that we could. Actually, I went to a Photokena meeting of the international photographic society, I guess this was actually in the 1950‘s and gave a paper on the theory of color photography. As a matter of fact, it was the paper for the entire audience and I didn’t know it was going to be that until I got there. I was scared to death. I got up in front of the audience as a young man and then gave this paper on the theory of color photography, but that was interesting keeping all of that theoretical work going along with the practical. We still were trying awfully hard to work out a film for motion picture use and now that the Kodacolor process had been invented, we could use that to make a negative, if that was the right thing. Well Kodacolor, Autocolor at the time, was much too grainy, much, not nearly sharp enough for motion picture use. All the uses of film then were big sheets or the roll film several inches wide, and it was just no way that the film was good enough for 35 millimeter, but we kept trying. We learned how to coat the film, thinner, and thinner, and thinner. Now that was all done in the manufacturing divisions but not all of it, but anyway, they were learning all the time how to coat thinner and thinner, and that made sharper pictures. The chemists were learning how to make the couplers more soluble so you didn’t have to have so much coupler solvent, trying to make the couplers more active, so we put fewer and fewer chemicals in the coatings. I mean everything you could do to improve sharpness was being done. Another invention was made about that time. It was discovered that there were sensitizing dyes that not only wouldn’t wander from one layer to the next, but wouldn’t wander from one grain to the next. If you put them in an emulsion, it would get on the grain, you could mix another emulsion together and have a mixed grain process where the green sensitive grains staying green sensitive and the red sensitive grains. So, there was a chance to make Kodachrome in one or two layers. We put a lot of effort into working out a Kodachrome film in one layer. For motion picture use, if that was the release print film where you make a lot of copies, the cost of that film makes a lot of difference. So we would visualize we’ll have a color negative film and we’ll print a positive from that, both of these with color couplers so that the color would come out all right, and then we would print that onto this monolayer film. It was a little complicated to process, but professionals at motion picture laboratories could do it and that would be a cheap motion picture film. So we worked for years on that program. Well first of all making the color negative, it wasn’t nearly sharp enough, but finally we had gotten some improvements in sharpness and some improvements with graininess. We decided working on roll film for the amateur, and we decided let’s make some motion pictures and see what it looks like. So we made some motion pictures, cut some of that film up for motion pictures and made motion pictures only about 1947 or ‘48, and printed them on a positive film that we were working on. And, boy, they were beautiful for just general quality. They weren’t very sharp and they were too grainy, but the general effect was really something. We showed these to top management and they said, “Look you got to make this work. That’s good. We want that.” So, we went to work to try to improve the graininess and the sharpness. I can remember to this day, another idea that popped out looking at some pictures over a white view box, an idea as to how to fix the graininess. It doesn’t make sense to people that weren’t really steeped in what was going on but the idea that the cyan layers, instead of coating it in one layer you coat it in two, and the magenta layer, instead of coating it in one layer you coat it in two. And you structure those layers right, it would improve graininess significantly. I just knew that would be the case and we tried it, and boy, it really did. Now I’m not going to explain why that works, but anyway, it did. It really worked. It upset everything else, it took a lot of doing to really get that worked out so you could really get nice pictures with it, but it worked and there we had a motion picture negative film. So the company decided well we’ll sell that motion picture negative, and we’ve got a positive we can sell, too expensive, we were still working on monolayer for the positive, too expensive, but we’ll sell this positive. This was about 1950, ’51 now, and we don’t know how people are going to make intermediates, they’ll have to figure that out. We’ll come along someday and have films that will make the intermediates, but we got to sell these films. So that was started. “The Royal Journey”, the Queen of England was traveling through Canada that was the first picture made on this combination of films. The Eastman color negative and the Eastman color print film, with no intermediates. No other picture was ever made like that, but that one was and it was quite successful. We were still working on this monolayer. That was the way to make motion picture positive, it just had to be. It was the cheapest film we could imagine. Another invention came along which completely negated that, and it was also an unbelievable invention. The multilayer film has many layers coated on it. You coat a layer; you set it up with gelatin liquid, a sort of gooey liquid, you set it up, maybe dry it, coat another layer on it, set it up maybe or maybe not dry it, but you got to set it up, and then coat another one on it. Somebody came up with the idea of, ok, let’s coat all of these different emulsions at the same time. We’ll have ourselves a little hopper out of this slit will come one emulsion, out of this slit will come an emulsion, and out of this slit will come an emulsion. They’ll roll right over each other; they’ll stay separate go down on the film base, coat them and dry them, and then you’ve got the coating. There was no way that was going to work, but it did.
MR. LARSON: After all that work, they would be mixed together.
DR. HANSON: They would all mix together. Well as a matter of fact, they stayed clean as a whistle. They do not mix. Our coating hoppers, which people called Joe Hoppers, coat of many colors, but there are six layer coating hoppers in use today. Now of course making motion picture positive with just one coating operation, you got to make the three or four emulsions anyway if you mix them and coat them you might as well feed them separately and coat them. That completely negated any need for monolayer and since it was pretty tough, that program was canceled out of a month. So that was the second big program that I was working on that just got canceled. But they got canceled by something better. They didn’t fail, they just got improved upon and something else displaced them. A lot of things happen like that, and something better comes along.
MR. LARSON: Oh, yes. Remarkable story.
DR. HANSON: So, that made it possible to have a motion picture process that was economically feasible, so we did go to work and work out the intermediate films. First of all, we made black and white separation positives. Then we made a duplicate negative. You coat those three black and white positives onto another negative and then you would print that negative onto the print film. That was commercially used for two or three years. Then we learned how to make an intermediate film with good enough characteristics so we could have the color intermediate positive put right back onto itself to make a color intermediate negative and then print that onto the motion picture film. Now that is the film that is in use today. Many improvements along the way, but that sort of film is in use to this day. We’ll all this time we were still trying to improve amateur film and we introduced the colored couplers into the Kodacolor roll film. Just as we were about to get that ready for the market, we had a problem with the government. Kodak was a monopoly we could not control the processing of Kodachrome ourselves. We couldn’t sell Kodachrome film with the processing price attached to the film. We were the only ones that could process it and we always looked at it as the processing was a part of the manufacturing of the picture. The process was much too complicated for the general public to do, but the Justice Department says, you can no longer sell the film with the processing included. So we quick decided well, we don’t really want to disperse the Kodachrome processing. Maybe one or two big people could do it, but let’s work out an Autochrome film which was a lot easier to process for 35 millimeter 35, for slides, that the general public can process. So we very quickly went to work and worked out a 35 millimeter Autochrome film. Now at that time, even though we had the color negative that was good enough for motion picture, Autochrome had not been thought to be good enough for 35 millimeter use. Actochrome was still big sheets or roll film, but applying all of the coating technology and the chemical technology to Autochrome it was possible to work out a slide, a 35 millimeter slide film with Autochrome. So in 1955, when the Kodak Consent Decree was signed and we gave up, we stopped selling Kodachrome film with the processing charges attached, we made Kodachrome process available to people, but we thought Autochrome is what they should do, and we also thought that Kodacolor is what was going to grow anyway. So this color coupler Kodacolor was worked out using the non-toxic developer instead of the toxic developer that had been used so that it could be processed commercially. In 1955, with that Consent Decree, color photography sort of became general. It was processed all over the place, Kodacolor prints were made all over the place, and motion picture film was available, so by 1955, I think you would say color photography was here. One of the problems was in making prints and they get exposed to light all the time and to the atmosphere is that the dyes in color photography are not the most stable things in the world, or weren’t at one time. So dye stability was one of the big problems that was studied all the way going back to the 1940’s people were beginning to learn about it. It took a lot of learning and empirical studyes before you knew which direction to take. One of the stories that the Kodak dye chemists tell that is amusing about dye stability is you don’t want to wait 25 years to see if a dye is going to fade in 25 years, you have to have accelerated tests. So, how do you define an accelerated test that will give you the right answer? Just take for example, the egg. Now, you put the egg in the refrigerator and it’s good for months; you put the egg out in the sun and in a few weeks you’ve got a rotten egg; put the egg in an incubator and in two or three weeks you got a chicken. I left out put it in boiling water and in a couple minutes, you got a hardboiled egg. So how do you design the test to, the rapid test to tell what is going to happen to an egg. Same thing to dyes some dyes are oxidized to destroy themselves; some dyes are reduced; some of them need moisture for stability; some of them are destroyed in the presence of moisture. So you’ve got to work out all these things and work out all these tests before you can really develop perfectly stable dyes. Now, this work is going on, but as of now, the dyes are almost achievably stable and color prints are quite stable and color motion pictures are quite stable.
MR. LARSON: Well that is a tremendous advance…
DR. HANSON: A tremendous advance in 30 years.
MR. LARSON: Early color prints really have difficulty…
DR. HANSON: Well the early Kodachrome slides, before 1938 are all gone now, they just faded. Now the Kodachrome slides made in 1938 on, in the dark, are essentially stable. I have some made in 1940 that are just kept in an album. They are just as good now as they were then. In the light those dyes fade some. A tremendous amount of chemical research has gone on in that study. Something like 30,000, 40,000 couplers have been made studying color and stability. Oh, that’s another point that I haven’t…
MR. LARSON: That’s a tremendous effort.
DR. HANSON: A tremendous effort, and millions of man hours of work. Designing a magenta which is exactly the right type of magenta, there are all sorts of magentas, and thousands of them have been made to get the right dye, exactly the right color. The dye, the coupler has to be reactive with the developer and so you have to learn chemically what sort of structures are reactive and what sort of structure isn’t. The chemical research that has gone just into this area is huge. Ok, well that sort of brings us up the point where color photography is here. It’s available to everybody, it isn’t that convenient yet, the speed of the films is not that great, 24, 16, or something. So and loading a camera is complicated. So, we set out to make it simpler. From here on, I think the quality is here, generally, ok, let’s make it easy, simple so people can use it. Increasing the speed, well I’ve told you a little bit about doing that. Well, all of that has been applied to photography. Increasing the sharpness by mechanical and chemical methods that work has gone on. Now, 1963, the cartridge camera was worked out. The Instamatic camera, Kodak began to sell that in 1963. Now that had the cartridge with the film in it which you can load right in the camera. Now actually, that is saying that when you take the picture, the cartridge is part of the camera. So the mechanics of seating that film, having the cartridge itself seat properly in the camera and the film sit properly in that cartridge so that it’s in the proper focal plane. That takes a lot more doing than people stop to think about just putting a cartridge in a camera, but all of those things had to be done. But also the design of that system was such that the film speed had to be twice what we had ever been able to make it before. That took just a lot of steady work, using all that was learned, and that was successful. One of the things about the Kodak business techniques at the time that amazes me is that in 1963, that Instamatic camera, the camera with the cartridge, easy loading camera was put on the market. That camera and film were in warehouses ready to go all over the world, so it was announced and available for marketing all over the world all at the same time. The stock analysts and the advertising people except those we want to, I mean all of it was kept a secret. And that was amazing.
MR. LARSON: Fascinating there that that whole new development which was…
DR. HANSON: And it was put in place with the competition and the advertising people not knowing it was there. These days products are announced about a year before they are out there…
MR. LARSON: That’s right.
DR. HANSON: …from almost everybody, but…
MR. LARSON: Right, when you try to go buy it, it’s not available.
DR. HANSON: It’s not available, but that one was really done very well that way. Let’s talk a little bit about the overall applications of photography.
MR. LARSON: Ah, yes.
DR. HANSON: The major thing is the pictorial application, of course.
MR. LARSON: That’s right. You mentioned before the fantastic contribution it made to the application, the x-ray.
DR. HANSON: The x-ray as early as 1896, film was applied to x-ray. 1928, RecordEc, recording checks and recording other objects and documents, but that started in 1928. Now the characteristics of that film are very different form the characteristics of the film for pictorial use. So a RecordEc film was worked out in 1928. 1929 sound on film. Sound is recorded in waves, or in dots, and the characteristics for a film on that are different from any other, but sound film was worked out in 1929. Codalift film for graphic arts, for making half tone screens that film has exceedingly high contrasts and no toe, no credition down here; it is almost straight down to white.
MR. LARSON: Black or white.
DR. HANSON: Black or white. That film was worked out. It took a special, very sensitive sort of process to make that happen. It’s only in recent years, in fact, almost recent months, that a very stable reproducible process can make that sort of a characteristic in a film, but that now is available. Reconnaissance film, I’ve mentioned that, the V-mail film during the war, RecordEc, sort of the same sort of film for that. The computer output microfilmer. Kodak worked out a very neat method of exposing film using lasers. The lasers emodulated by a gusto-optic device to print the digits. So a computer output microfilm with laser exposure with gusto-optic control is on the market now. I was always amused by that. Nuclear tracks, nuclear tracks, nissans, all sorts of rays make tracks in photographic emulsions, and let’s see, it was Cecil Powell in 1940 discovered the nissan in a photographic emulsion, the track in a photographic emulsion. And he got the Nobel Prize in 1950 for that. That was the fact that it was photography had nothing to do with his prize, but it was photographic emulsion that he was using, or the photographic emulsion.
MR. LARSON: The characteristics film had to be done.
DR. HANSON: That’s right. Astronomical uses. Now that is a special use. The films are exposed for 4 to 6 hours and there is a lot of haze and background so the characteristic that has to be put into astronomical films has to be very carefully understood and designed. An interesting concept called detective quantive efficiency is very important in astronomical films. A study of that characteristic of films and how you maximize that rather than some other characteristic is what you do when you design an astronomical film. Another aspect of it is exposing for 6 hours. Now photographic film, there is a law called the Reciprocity Law, exposure time and intensity are interchangeable. If you double the intensity of the light, in half the time you got the overall effect. Well, in fact, it doesn’t work that way. There is a reciprocity failure and the mechanism of it is now known pretty well, but a film that is going to be used for astronomy where the exposure is 4 hours has to be designed very differently where you’re going to expose it for a thousandth of a second. All of those things have to be learned and used. There was a film called bi-mat that had a great future at Kodak people thought which was, all the chemicals were put into a layer and they were put in contact with the exposed film, they’d developed it and sort of drew out of there all the excess and you came away with a negative. Very much like the Polaroid process which I will talk about in a little while perhaps, but this bi-mat film never did develop an application until the lunar orbiter came along. Back in the early ‘60’s when they were taking pictures of the moon prior to landing on the moon, they put the lunar orbiter up there with bi-mat film in it which could be developed on the spot and then those images radioed down and so that was used on the lunar orbiter.
MR. LARSON: That’s very interesting.
DR. HANSON: Ok, gee, where are we?
MR. LARSON: Well, we…
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DR. HANSON: Along about this time, I got moved out of color photography for a little while. I became the assistant director of research and the whole color photography activity, well most of it, was sort of taken out from my responsibility and I was given responsibility for the physics and chemistry and all the new things and I was sort of, even though I had been working pretty much on practical things, I was sort of a theoretical person and interested in the new things and so I got involved in physics and magnetic tape and electronics and chemistry, basic chemistry and that sort of thing. But I kept involved in, my involvement in color photography never the less. One of the things that I was very excited about for a while, turned out to be super 8 millimeter. Now 8 millimeter film which was the major amateur film is cut from 16 millimeter film, it has perforation holes, big holes that it’s pulled down with as it moves through and a lot of space between the pictures and there was a lot of waste on it. I had worked awfully hard to improve the sharpness of films and I figured, gee, if we just used more of that space that would improve the sharpness of the picture a lot more than any change in the film I can imagine. And so I began to promote the idea of using little bits of perforations and smaller intermediate lines and make the picture just as big as you possibly can. People said you’re not going to change the format at this time, but anyway, we went with it and we finally sold it to management and we came out with super 8 millimeter film, which was a lot sharper and a lot better than any 8 millimeter had been before. It took a lot of mechanical doing; it was all mechanical of course. But that did get done anyway.
MR. LARSON: I can remember how much sharper and more satisfactory it was.
DR. HANSON: Much sharper pictures. One of the fellows in the laboratories working on the super 8 was interested in amateur photography in general, amateur movie photography. He was just doing all sorts of experiments and he wanted to, film speed was improving. We were using higher speed films in 8 millimeter. Now the 8 millimeter lens is a pretty small thing. If you have a high speed film and you close down the aperture of the lens you run into a refraction limitation and you begin to lose sharpness. So he wanted to see if he could improve that. So he tried to get a shutter in the camera, the movie camera, there is a shutter that goes around and blocks the light when the film is moving. And so he wanted to get a shutter that he could close down and cut down the exposure by cutting the shutter rather than by closing the aperture of the lens so he wouldn’t lose the sharpness. Well he ran into a very strange phenomenon. As he closed the shutter down to a very small angle so the exposure was very short, he got very jumpy motion. Anything in movement would be so sharp that he would get very jumpy motion.
MR. LARSON: Oh yes.
DR. HANSON: And that was not good. Well he immediately began to think the other way. Ok, let’s open up the shutter and see what happens and he opened up the shutter so something like 330 degrees, it has to be a very fast turning shutter, but anyway, it could be done. He got very smooth action and that also made him think now that is also giving me two or three times the exposure that I use to get, maybe I can begin to take pictures without any lights. Now the lights for motion pictures at that time were a nascent. He began to think of available light. He got himself a camera with about a 330 degree shutter and got some of the highest speed Autochrome slit 8 millimeter and began to take pictures and sure enough he could take pictures in a room like this perfectly well exposed. And in a dark laminated bar, and they weren’t quite exposed enough. Then he realized the concepts called TEMS, T-E-M-S, terminal exposure modulated scene. Now the eye adapts to light.
MR. LARSON: Oh yes.
DR. HANSON: And everything looks about the same brightness until you get down to a certain level. And then at that level as the light goes down you notice it gets darker and darker and darker. That level of illumination is about 7 foot-candles. Anything below 7 foot-candles looks dark to the eye. That is the way the picture should look. I mean you don’t want to take a picture in a dark bar and have it come out looking like it was bright daylight, or you don’t want to take a picture under moonlight and have it come out looking like it was broad daylight, which you could do with a longer exposure. So that terminal exposure modulated scene of 7 foot-candles sort of set the speed of the film that was required for available light photography. Now everybody thought, oh, available light photography would take essentially infinite film speed so no one had even tried it, but now that film speed was in sight with that sort of camera and with a very big lens. So he put together a lens of aperture 0.9 and a shutter of 330 degrees, he got some Autochrome film, 160 speed Autochrome, split 8 millimeter, and he began to take pictures. Sure enough he got excellent pictures in a dark bar, it looked like what you photographed. He couldn’t sell the idea to the marketing people, to the camera people, to anybody. He was getting all these exciting pictures and nobody would pay any attention. At that time, the chairman of the company, Dr. Albert K. Chapman was coming down to the research laboratory once a week and spending all morning and having a review of what was going on. I don’t know of any other company or person in the world like that.
MR. LARSON: That doesn’t happen.
DR. HANSON: It doesn’t happen, but every week he was down there each morning, I mean one morning every week getting familiar with what was going on. One morning he was down there and this fellow, Gorman who was doing the available light was projecting for somebody else. He wasn’t part of the show, but Dr. Chapman had heard him talk once or twice about something he was doing. He looked around and said, “Gorman, what are you doing these days?” He said, “Dr. Chapman, I’m glad you asked. Let me show you this.” So he went and got some of his available light films and he began to talk about what he had done. From then on, the camera people and manufacturing people, and the marketing people were interested.
MR. LARSON: That’s amazing.
DR. HANSON: But Dr. Chapman picked it up and so others began to cooperate and a system was worked out and put on the market. Well apparently, the marketing people had never really quite understood, or never quite got as enthusiastic about it because within a couple of months everything was on backorder. That program went much bigger than anyone expected it to. It was two or three years before we were making enough film and cameras to fill the need.
MR. LARSON: Oh yes. That is amazing.
DR. HANSON: But that was one guy with his idea and it ended from work that he was doing heading in the opposite direction.
MR. LARSON: That’s right.
DR. HANSON: But he followed it right along there. Ok, now we’ve got available light photography, we’ve got the loading camera, the cartridge loading so it’s simple. Now let’s make it really simple. Let’s make the camera small enough to put in your pocket and you have it with you all the time. in fact one of George Eastman’s objectives way back in 1900, he used to say, “I’m going to make the camera as simple as the pocket pencil.” And so that is what we set out to do in the late 1960’s. And by 1972, the pocket camera was put on the market. Now that pocket camera with the little bits of 16 millimeter film, well, when we had come out with the Instamatic, the cartridge load 35 millimeter, we had had to speed up the film and make it less grainy. When you go to the pocket, we had to speed up the film and make it less grainy. That really strained the photographic system, but it was done. In 1972, the pocket camera was put on the market, and it really took off and it made photography available to everybody, children and everybody. Ok. I’m going to sort of step aside and talk about instant photography.
MR. LARSON: Oh yes.
DR. HANSON: Because back in the 1940’s Edwin Lamb developed instant photography, where you take the picture and in 30 seconds you take it out of the camera and you get the finished picture. That was highly successful. He had developed quite a business and he wanted to do that in color. In the late 1950’s, he came to Kodak with some chemistry that would make instant color pictures. Kodak and Polaroid worked together on that for several years. Kodak worked out, perfected the process, and made the Polaroid film which went on the market in the early 1960’s. Well Kodak wanted to have its own color film, own color instant film. None of Lamb’s patents were available to Kodak. So in the late 1960’s Kodak decided, ok, we’ll work out an instant product that it is free from Lamb’s patents and go on the market with our own instant film. A program was set up called PL9-76. This was established in 1968, ‘69, ’70, one of those, I’m not sure. But PL9-76 meant a project of the research laboratory to go on the market in 1976.
MR. LARSON: Oh yes.
DR. HANSON: Thousands of people worked on that in the plant and in the camera area, and in the film, manufacturing and research, in the chemistry, in the physics, and in 1976, the Kodak instant camera went on the market.
MR. LARSON: Oh yes.
DR. HANSON: Now that just shows that if you’re really determined and you do what it takes, you can accomplish a lot of things.
MR. LARSON: Yeah, it’s sort of like we’ll go to the moon by 1970.
DR. HANSON: The moon by 1970, yeah, they really can be done if you set your mind to it. Now whether or not this was a good thing for Kodak to do and sort of take its emphasis off of other things, that’s debatable and people are still debating it. That was a complete success. About this time, I became director of the research laboratories and was not that much personally involved with the work, well fairly closely anyway.
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DR. HANSON: The idea was developed that the film should not be in camera in the roll form, but should be in a disc. There are several advantages to that. It wouldn’t curl. You could advance it easily in the camera and you could have a nice neat small camera, and so work started on a disc camera and I spent my last four or five years at Kodak sort of resisting that program or at least seeing how tough it was going to be to get a good enough picture in the very small film you were going to have in that disc. So as I say, I spent my last few years sort of resisting that program. Well in 19- whenever, oh, where are we? In 1982, the disc camera came on the market. It was a big hit. I was almost right on the quality not being good enough, but it was just good enough, and by now it’s better, so that they made it. So, now everybody has a disc camera and takes simple pictures. Pictures with no problems, automatic advance, fixed focus, you don’t have to focus it. It’s quite a system.
MR. LARSON: Yes, that is so convenient. You just put it in your pocket…
DR. HANSON: Put it in your pocket and it’s there all the time.
MR. LARSON: Women can put them in their purses. When they think about it, and it works out just fine.
DR. HANSON: So that just about brings us up to date with the cameras and the film and where we are today. There are millions of pictures that are made. I use to go around lecturing about the science and development in photography. Back in the 1960’s I remember a statement that I use to make, that I think I’m going to quote right here because I enjoyed it so much. Now I’m going to have to read this. “In 1930, an editorial in the Prim Rose Annual said, and I quote, ‘To imagine that dividends can be paid to shareholders in a process that seeks to supply the public with snapshots, or portraits in color is extreme foolishness.’ Now the 1966 Eastman Annual Report says, ‘According to recent trade estimates, more than 3 billion pictures were made in 1966 by amateur photographers in this country, and 6 of every ten were shot on color film.’ In the April ’67 issue of Photographic Journal, Dr. Hoyd Varden states, ‘There are thought to be 1,350 color finishers of amateur films and prints for the general public. About 900 in plant color laboratories operate for their own needs, including industrial firms, school photographers and so forth. In addition there are 690 known custom color laboratories.’”
MR. LARSON: Amazing developments.
DR. HANSON: After the 1930’s a lot happened.
MR. LARSON: That’s right. That’s amazing.
DR. HANSON: That covers the film and its development and the camera some too. The camera is an important part of taking a picture. An awful lot has happened to cameras in 30 or 40 years. Back in 1938, the photoelectric exposure control was put on the camera by Kodak. That was not successful. Interesting, it was before it’s time and it disappeared for a while, but then it came back and automatic exposure control is a very important part of cameras these days. Rare earth glass was developed in 1941 and that gave a different ratio of index of refraction to dispersion and it made it possible to design better lenses. Aluminized lenses came along in 1946 that cut out the lens glare and that was an important contribution. Then computer designed lenses made it possible to make a very complicated lens in 4 elements that use to take 9 elements. So just playing the use of the computer made a lot of difference to lenses. Aspheric lenses, lens instead of being spherical to the ground, if it could be molded into an aspheric shape, again, that makes it possible to make a simpler lens that’s corrected for astigmatism and achromatic problems and so forth. So, a great deal has happened in the lens design area. Autofocus mechanisms have come along and that has made a tremendous difference in the simplicity and use of a camera. One type of autofocus is sending out a radar signal and then when it bounces back its in focus, but you can’t take a picture through a glass window with that for example. But another kind is maximizing the signal when the picture is in focus, the blacks and the whites are sharply defined and reading the brightness across an image gives you spikes of intensity and maximizing that is a method of telling when you are in focus. So maximizing that measurement is the way that autofocus is done now. The autofocus camera you don’t have to focus, it is just there, its fine. Shutters have been improved so you can get a thousandth of a second or a second, very accurately and that is absolutely necessary. Reflex lenses that you can look in it and see what you’re photographing and not get the wrong picture. Automatic advance of the film, like this disc camera the film advances automatically. You press a button and you’re ready for the next picture. Of course these are all good for the company too. You take a lot more pictures. But all of these mechanics and optics have played a very important role. I’ve mentioned the coating techniques in coating the film. I mean, a tremendous amount of progress has been made in the coating techniques that make it possible to make these films today. All of these advances simplify our taking pictures.
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DR. HANSON: Well I think that just about takes us up to where we are and where photography is these days.
MR. LARSON: Well, that’s been a wonderful exposition of the history of photography so that we got a very complete record there. Perhaps just to round out this whole picture, there was one point there in your presentation where you mentioned the diversion in regard to the defense work during World War II and you, of course everyone in the nation was mobilized including Kodak to assist that. I was wondering if you could to round this whole picture out if you could describe your participation in that to just round out the whole picture.
DR. HANSON: Yeah I’d be very happy to talk about my involvement in the Manhattan Project and Oak Ridge, Tennessee. As I said along the way in 1943, I joined the Manhattan Project. I had seen people from the research laboratory disappearing and people went off on to a project and nobody was told where they were going and I sort of offered my services to Dr. Mees. I said, “I see a lot of people are going out to war. I would be happy to offer my services.” And he said, “Well, gee, I hadn’t thought about you going.” He said, “Ok, sure.” So, I was sent to Berkeley, California, to the radiation laboratory to learn the beginnings of the electromagnetic separation of uranium. I had gotten my degree there and I had known Ernest Lawrence, in fact he had been on my examining committee for my Ph.D.
MR. LARSON: Oh, that’s very interesting.
DR. HANSON: Yeah, so I knew him. I had met Oppenheimer out there at Berkeley during college. [Linus] Pauling I guess he wasn’t involved then, but I had met him. But anyway I went back out to the radiation laboratory to sort of get a basic knowledge of what was going on. Then I went back to Rochester and became involved in some of the chemical operations that were being developed there in the Rochester Research Laboratory. Then very shortly, I came down to Oak Ridge, Tennessee, where I was to become the head of the Chemistry Division of the Tennessee Eastman operation. Tennessee Eastman was operating a plant, the electromagnetic separation of uranium and it was a physics operation, there was an awful lot of chemistry involved, but in the preparation of the whole project, I think the chemistry had not been quite developed as the physics had because it was a physics operation and we had problems.
MR. LARSON: Of course, at that time, the physicists believed the only problems were physics problems.
DR. HANSON: Yes.
MR. LARSON: The others were incidental.
DR. HANSON: Yes, well we had problems that we had to solve as we went along, and we did. We had a wonderful crew of people there, like Clarence Larson and we solved problems that were coming up every day. We made the thing work. I don’t think I need to go into the details of that, but we made the thing work and you know the story of that. Life in Oak Ridge was sort of pleasant, but it was very strenuous. My wife loved it and I loved it. We were the early ones to leave at the end of the war. Dr. Mees had come down to Oak Ridge and asked me to come back to Rochester. They were making some changes in the color photography work and wanted me to come back to Rochester. So I went back to Rochester in May 1945. That was before the final development before anybody knew whether or not we had been successful. I didn’t know any more from then on for a while.
MR. LARSON: But of course at that particular time, the die had been cast, the material had been produced.
DR. HANSON: The material had been produced and delivered.
MR. LARSON: So that the job was essentially done for that particular section.
DR. HANSON: I can remember there were two sections to the plant, the alpha that would enrich the uranium up to 7, 8, finally ten to 12, and the beta that would take it up higher and at first the output of the alpha plant they wanted us to send out to Los Alamos. All we could make we sent out there, until finally they said Ok. Don’t send anymore. So we knew that amount meant something. We can sort of guess that that amount had a meaning to it.
MR. LARSON: Well, that amount that was delivered gave them the numbers that were needed for the final product. So that must have been a very interesting part of your career.
DR. HANSON: It was very interesting. I mean all of us, many of us had some responsibility for people’s behavior and for chemistry and for a lot of things that none of us would have had under any other circumstance. So people grew up pretty fast at Oak Ridge.
MR. LARSON: That’s right.
DR. HANSON: It was a wonderful experience.
MR. LARSON: Yes. And of course you have many of your colleagues then who had come from Rochester and Tennessee Eastman returned including subsequently, didn’t the president or chairman of Eastman Kodak spend some time in Oak Ridge.
DR. HANSON: Yes, he came down. He came down and visited on occasion. Yes he did. Yes. One thing that sort of amused me afterwards was my name could not be in the newspapers or any publicity because my Ph.D. at Berkeley had been with G.S. Lewis and in heavy hydrogen. Now there was no connection between that and what I was doing, but the powers that be had looked up all that sort of stuff and the fact that I had been involved with heavy hydrogen back then meant that my name could not be in any publicity or any newspapers, which I didn’t know at the time.
MR. LARSON: Of course, heavy hydrogen played a role.
DR. HANSON: Yes, in other aspects of it. Yes, it did. Now, the Tennessee Eastman operated this plant, Y-12 plant in Oak Ridge and there were 2 or 300 people that came down from Eastman Kodak Company that were in management positions. Now this story I am about to tell intrigues me as a characteristic of George Eastman and the Eastman Kodak Company that he founded, is at the end of the war, all of the plants that were in Oak Ridge, there was a number of them, and took a vote whether or not the employees would join a union. None of them were unionized, but right after the war, all of the plants took a vote as to whether or not they would join the union. All of the plants except the one run by Tennessee Eastman voted to join the union, and at that plant the people voted not to join the union. Now 2 or 300 management people from Kodak with their policy and the way they handled people and the operation influenced those people that they didn’t need or want a union. Now that tells you something about that company.
MR. LARSON: I think the people all had a sense that they were participating in an important role in the objectives and that feeling of participation meant that their voice was already being heard.
DR. HANSON: That feeling apparently didn’t develop in the employees of other organizations down there.
MR. LARSON: That’s right. That really is a very important point.
DR. HANSON: It’s an important point as far as industrial management is concerned, yes.
MR. LARSON: All right.
DR. HANSON: Yes. Well I think that brings us here.
[End of Interview]

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PIONEERS IN SCIENCE AND TECHNOLOGY SERIES
ORAL HISTORY OF DR. WESLEY HANSON
Interviewed by Clarence Larson
Filmed by Jane Larson
Date Unknown
Transcribed by Jordan Reed
[Pre-interview conversation]
DR. HANSON: You get to test the sound?
MR. LARSON: I’ve already tested it.
DR. HANSON: You’ve already tested it so it’s all right. [microphone feedback] Whoops. Little ring there.
MR. LARSON: All right and she looks at the monitor there.
DR. HANSON: I noticed her name in the, as doing all the work in these things, the earlier things. Let’s see, do I want that buttoned? I guess I do, I don’t care.
MR. LARSON: Now let’s see, I want to move this light so there is nothing on his glasses. [inaudible] Now see, when you turn this way it will, but you won’t ever turn…
DR. HANSON: I should turn more than this far.
MR. LARSON: Yeah. That’s right. So then there is nothing on the glasses.
DR. HANSON: If I can turn over this way, but why would I? Now, tell me when it hits the glasses when I come this way.
MRS. LARSON: Not yet.
DR. HANSON: Not yet?
MR. LARSON: I think I moved it. There!
MRS. LARSON: But that’s too high.
DR. HANSON: I won’t need to go that far anyway. I need to wipe off my glasses. Got little spots from that light over there.
MR. LARSON: Do you want to try the zoom? All right, that looks fine. Well, as I said, we’ll make it run as long as it’s natural. The tape is two hours, but if it runs over that we’ll just put in another tape. That’s all there is to it.
DR. HANSON: I don’t think my life will last more than two hours. (Laughter)
MR. LARSON: Ready, Jane?
MRS. LARSON: Ready. It’s on.
MR. LARSON: Ok, well fine, I think we can now start. Today we have the privilege to interview Dr. W.T. Hanson, whose distinguished career in photographic research has made key contributions to the development to modern color photography and many applications to photography through science, technology and art. It is a privilege to introduce Dr. Hanson. Please proceed, Dr. Hanson.
DR. HANSON: Yes, thank you. Well I might as well start at the beginning.
MR. LARSON: Very good.
DR. HANSON: I was born in Georgia. Both parents were school teachers and lived in the country. We lived on a farm, but both my parents taught school and as a youngster they taught me at home. So I started school in the third grade at age seven. A little bit out of my age group, and I was out of my age group for about 30 years, but that didn’t seem to make any difference.
MR. LARSON: Fine. What city?
DR. HANSON: Smyrna, Georgia, which is about 15 miles out of Atlanta.
MR. LARSON: Yes, I know the location.
DR. HANSON: I walked about two miles to school and home. I owned ten cows as a child and milked the cows each morning before going to school and then again after coming home from school. So I had a busy life as a youngster.
MR. LARSON: Yes, that kept you out of the usual adolescent diversions.
DR. HANSON: Yeah, very much so. Very much school. So I started school in the third grade. I went to summer school and skipped the fifth grade. Graduated from high school in three years and at age 14 applied to college and was a little too young to get in. So I had to work for a year before going to college. Then I went to the University of Georgia at the age 15. I decided I was going to be a civil engineer and studied civil engineering and physics and that sort of courses to start with and my first year at college I took a chemistry course and the professor must be the person that lured me into chemistry because I was crazy about the professor and the course. So after one year I changed over to chemistry as a major and graduated in three years with a B.S. degree in chemistry. At the end of that three years, or in the middle of that third year, which now was 1929, a Dr. Billings from the Eastman Kodak Company who went around interviewing students at various colleges came to the University of Georgia and I had an interview with him. He offered me a job for the summer with Eastman Kodak Company in Rochester, New York. So that summer after I graduated, I went up to Kodak and had a very fine experience working there that summer.
MR. LARSON: That must have been a real privilege meeting a famous pioneer in photography, Dr. Billings.
DR. HANSON: Well, he wasn’t that much of a pioneer in photography. He was in the personnel part of it.
MR. LARSON: Oh, I see.
DR. HANSON: It was Eastman who was the name of the pioneer who was so important in photography at the time. And Eastman I had heard of even then. But I didn’t get to meet Mr. Eastman. At that time, Mr. Eastman was in his 70’s and I was a lowly student down in the laboratory, and I didn’t meet him. I’ll say more about that a little bit later. But one of the things I did that summer was to learn to blow glass. I made a lot of equipment out of glass in the laboratory there and I spent practically all of my noon lunch hours blowing glass because I enjoyed it so much, which I used a great deal in my graduate work later on.
MR. LARSON: If someone doesn’t have the skill of glass blowing in chemical research, he is severely handicapped.
DR. HANSON: He is severely handicapped, but probably not anymore, but in those days that was the case anyway. Well, after that I went back to Georgia, for two years and got my master’s degree in chemistry. While there I applied for a fellowship at ten colleges all over the United States. I picked out the big colleges and applied to ten of them. This was now 1932, and I didn’t get a fellowship anywhere. So I decided I would go to Berkeley because I had studied Louis and Randall, the text book of thermodynamics, the famous textbook. I knew those two names so I went to Berkeley.
MR. LARSON: As a matter of fact, I still have, I think, my Louis and Randall thermodynamics text, published first in 1924, or something like that.
DR. HANSON: I do too. I have mine too. Well, the day I left Smyrna, Georgia, to drive with a bunch of friends to California, I got a letter from the University of California saying that they were all full, please don’t come. I put that letter in my pocket and I went right on anyway. When I got out there they asked me if I received that letter, this was one time I did tell a lie. I said, “No, I hadn’t received the letter.” They said, “Well, since you are here, you might as well stay.” So I stayed. (laughter)
MR. LARSON: That is a remarkable story.
DR. HANSON: It is a true story.
MR. LARSON: I should mention at this time that you were in very good company because Linus Pauling had a similar situation and he applied for graduate work at the University of California and he was also turned down.
DR. HANSON: Is that right?
MR. LARSON: So you are in very good company.
DR. HANSON: So the first year, I went to work for Randall and I didn’t get to see much of him. He was very busy writing books still and I didn’t see much of him. The second year, I worked for G.N. Louis, which was very fortunate because he was a wonderful person to work with and for. He was of course the dean of the college and the dean of chemistry almost at that time. That was a very wonderful experience. And in 1934, two years later, I got my Ph.D. degree. At Berkeley, the graduation is held pretty early, in fact in May. Most colleges are later than that, but my birthday was, is the 28th of May, and they had the graduation the 25th or 26th, and I was still 21. So I can say I got my Ph.D. when I was 21 years old.
MR. LARSON: That is really remarkable. It should serve as some sort of record for getting a Ph.D.
DR. HANSON: Almost, almost. Of course I was 22 a couple of days later, but I was 21 when I got the degree. So I wrote to Kodak, I said I’ve got my Ph.D. degree now. I’m ready to come to work. I had a letter back from Kodak saying sorry we don’t have any jobs. This was 1934.
MR. LARSON: Yes, well that was a time in our history where jobs for both graduate and undergraduate students were almost non-existent.
DR. HANSON: Almost non-existent. That was the depth of the Depression. Well I waited a week and I wrote back to Kodak and I said I am very anxious to work at Kodak and they wrote back and said they don’t have any jobs. So, I waited another couple of weeks and I wrote them saying I haven’t applied anywhere else, I want to work at Kodak and I certainly do want a job. About a week later, I got a letter saying come to Rochester for interview, be prepared to stay. And so I went to Rochester in July of 1934 and have been there ever since.
MR. LARSON: That’s a remarkable story. Shows that persistence pays off.
DR. HANSON: Persistence pays off. I have given advice to two or three college students that persistence pays off and in a couple of cases it did for them too. So it’s worthwhile sometimes anyway. I started in the photo micrography department which was studying some miscellaneous subjects, but very shortly I moved over into color photography. That subject really attracted my attention in my life and that is where I spent most of my life from 1935 on in color photography. Can we cut a minute?
[Break in video]
DR. HANSON: A little bit about photography, just a, what it’s all about, or the history, how it came about.
MR. LARSON: Yes, well that background would be very helpful.
DR. HANSON: Actually, we go back all the way to Leonardo Da Vinci, who dealt with the camera obscura , which was the box for making images. Of course you have to start with the image and recording it is what photography is.
MR. LARSON: Oh, yes.
DR. HANSON: It was as far back as 1750, that a chemist named [Johann Heinrich] Schultz learned that silver salts were sensitive to light and then a little bit later it was found out that the light effect on the silver salt was to turn it to silver, and then every ten or 15 years, some new knowledge about silver salts developed. Other materials are light sensitive and in fact the first photograph that was called a photograph was made by bitumen , made by [Joseph Nicephore] Niepce in France that was an organic material that hardened by light. But still it was very shortly after that that silver salts came back into the picture, and in 1939, [Louis] Daguerre worked out a process using silver on a copper plate and developing it with vapors of iodine and the Daguerreotypes became important, and that was really the first photographic process.
MR. LARSON: I think you may have made a typographical error. You said 1939. You meant…
DR. HANSON: I mean 1839. I certainly did. Ok, that is right.
MR. LARSON: Which of course was a fantastic development.
DR. HANSON: That was quite a development and it had a lot of commercial use. I mean the Daguerreotypes these days are museum pieces. But there are quite a lot of them around, but it had a lot of commercial use.
MR. LARSON: The National Portrait Gallery has quite a line, a collection of the Daguerreotypes.
DR. HANSON: Yes, but silver salts in carriers rather than just on a metal plate in collodion , which had to be a wet plate process. You had to sensitize the collodion with the silver salt and never let it dry. So you had to do this in the dark end of the camera and then take the picture and develop it right then. So that was bulky. Finally, about 1870, silver halide in gelatin appeared to be a very sensible light sensitive material. At that time, it wasn’t very light sensitive, but it was sensitive enough that it began to be used, which brings me to George Eastman. George Eastman was a bank clerk in Rochester, New York, and he was interested in photography himself and he set out to make photographic materials which he himself would use, and decided that he would go into the business. He started in a very small way, still working as a bank clerk, but trying to make photographic plates out of silver bromide coated on glass. He was quite successful in 1880. He went into business and began to sell these plates. In 1882, he began to have complaints from a lot of customers that they felt the plates that they had were insensitive. He ran thousands of experiments and couldn’t find the trouble. He was buying gelatin from England and he and a friend went to England to just find out what they could find out. They did find that one particular batch of gelatin that they had bought was causing the trouble. There was something wrong with it and it destroyed the sensitivity of the plates. He replaced any plate that anybody had ever purchased. That was the way he did business right from the beginning. He replaced every plate that had ever been purchased and established his reputation that way. In 1886, he hired a chemist to do research. It was probably very nearly the first research in industry in the United States.
MR. LARSON: It must have been.
DR. HANSON: And he, it was very close to the first. And he hired this chemist to work out a film base so that they wouldn’t have to use glass plates. To use a flexible film and it would be lighter and more convenient.
MR. LARSON: Before that time, there had been no flexible films?
DR. HANSON: There had been the use of paper.
MR. LARSON: Oh, yes.
DR. HANSON: It had been coated on paper.
MR. LARSON: Oh, yes.
DR. HANSON: And then he went through a period of stripping plastic on paper. Then he worked out the clear plastic that did the job. So then by 1891, when [Thomas] Edison invented the motion picture, Mr. Eastman had the clear film and was ready to work with Edison on the motion picture films. He was right there and ready to work on the motion picture films as soon as Edison wanted it.
MR. LARSON: It would have been very difficult to invent the motion pictures using glass plates.
DR. HANSON: Yes, it would. And Mr. Eastman asked Edison, “What size should the film be?” And Mr. Edison said, “Oh, about that wide.” And that is how 35 millimeter film was developed.
MR. LARSON: That’s amazing.
DR. HANSON: Yes, it is. In 1895, x-rays were observed. In 1896, Mr. Eastman had a film ready to record x-rays. That just shows how alert he was and how he was staying in touch with the scientific world and working out applications of photography for whatever there should be.
MR. LARSON: That is an amazing story in science that this one invention and development just paved the way for x-ray applications.
DR. HANSON: Just paved the way for x-rays, that’s right. That’s right. Now another aspect of his character, the x-ray film, the motion picture film, and the film base that he had worked out was nitrate, which is very flammable. So he immediately set out to work out a more stable film base. By 1908, he had worked out safety film; this chemist had worked out safety film. Now, he tried to get states to pass laws that they couldn’t use nitrate, that they would only use the safety film. The safety film didn’t have the same quality that the nitrate film did, but nobody was interested and motion picture film was on nitrate until about 1948.
MR. LARSON: It persisted that long, despite of the danger.
DR. HANSON: It persisted that long. X-ray film was on nitrate until about 1929. There was a major fire in Cleveland of nitrate film and after that x-ray film was put on acetate film instead of nitrate. Now, I’m sort of jumping a head a little. In 1923, that company first marketed amateur movie film in the 16 millimeter form. Now that was on acetate film and even when I joined the company ten to 12 years later, we were not permitted to slit any film, any nitrate to the 16 millimeter size. I mean, Mr. Eastman said there would be absolutely no inflammable nitrate film in the 16 millimeter size which goes into people’s homes. So he was very safety conscious from the beginning. He was a very conscious person of safety.
MR. LARSON: I have never heard that story before. We all know of course that the nitrate base is also in a form of gunpowder.
DR. HANSON: Yes, that’s right.
MR. LARSON: It’s terribly dangerous. I believe that Cleveland fire killed…
DR. HANSON: I don’t know the story of it, but some people were killed, yes.
MR. LARSON: I think it was 25 people. That is a very interesting story about how that developed. I’ve never seen that before. It was very interesting.
DR. HANSON: Now that is just the kind of person he was. Now in 1911, he visited the chemical industry in Germany and some of the leaders of that industry asked, “Well, now tell me about your research laboratory.” And he says, “We do a lot of research in the plant,” and they did. But these folks said, “Don’t you have a research laboratory that does fundamental research?” And he said, “What we think we do is fundamental research, but what we do is done all in the plant.” Well that got him thinking and wondering about a research laboratory. And so he asked some of the people in Germany, he said, “If I were going to set up a research laboratory, who should I get to head it?” There was almost unanimous opinion, it should be Dr. C.E. Kenneth Mees, who was in England. He was a managing director of Wratten and Wainwright. He had been an early pioneer in studying this science of photography and was a business man and a scientist. And so Mr. Eastman went over to interview Dr. Mees. By the way he had met Dr. Mees a few years earlier when Dr. Mees visited the United States. But anyways, he went in and asked Dr. Mees if he’d come and head a research laboratory in Rochester and Dr. Mees said he had a commitment of Wratton and Wainwright. So Mr. Eastman bought the company Wratton and Wainwright and Dr. Mees moved to Rochester.
MR. LARSON: That’s amazing story. In order to get the man, he had to buy the company.
DR. HANSON: Now, he didn’t go around Mees’ back to do this. Mees and he sort of worked out this deal that he should buy the company, but he did buy the company and Dr. Mees came to Rochester, in 1912. One other thing about Mr. Eastman, I mean, he and the company is just worth knowing about. In 1918, during World War I, we had been getting a lot of, chemicals, organic chemicals, not just the Kodak Company, but the whole country, got organic chemicals from Germany.
MR. LARSON: Oh, yes.
DR. HANSON: And that source was cut out. So in 1917 I guess it was. Mr. Eastman set up a laboratory to manufacture organic chemicals and Eastman Organic Chemicals is still available to colleges and people that need them today.
MR. LARSON: Oh, yes. Of course that, in chemical research we always turn to Eastman Fine Chemicals for a supply of chemicals. Almost every research laboratory in the country did that.
DR. HANSON: Yes, well that started in 1917, during the war.
MR. LARSON: That’s very interesting as to the origins of that.
DR. HANSON: At the end of the war, the Eastman Kodak Company rebated to the government all of the profits that they had made out of government contracts during the war, World War I. Now, that’s another characteristic of the company.
MR. LARSON: That’s a very interesting story and one which I had never heard before.
DR. HANSON: In the Second World War, V-mail was used, I’m jumping way ahead, but still this is part of the story. V-mail was worked out for cutting down the loads of ships, I guess there weren’t airplanes carrying around mail in those days, and all the letters to soldiers were microfilmed and sent on film and were reprinted at the site. This was worked out in England and then used first by the English Army and then by the American Army, but it was worked out in England. By the end of World War II, all of the profits made of that operation were given back to the English government.
MR. LARSON: Oh, yes.
DR. HANSON: So it really was, he as an outstanding man, and the company that he developed, you can see that I am very enthusiastic about it.
MR. LARSON: That’s a very interesting, valuable aspect.
DR. HANSON: Well now, my life was built around color photography. So, let’s get on to color photography.
MR. LARSON: Well fine, ‘cause that of course, that development is one of the most fascinating scientific and technological advances of our country.
DR. HANSON: It is a very interesting one and has been very successful. You might say it started back in 1861. Clark Maxwell in England demonstrated that color pictures could be made by photographing a subject with red light, and green light, and with blue light and then projecting pictures through a red filter, and a green filter, and a blue filter, superposed and that those three would make a full color picture. Very soon after that a fella named [Louis] du Hauron in France, showed that you could make a color picture by superimposing, not projecting three, but by superimposing three pigments which were yellow, magenta, and cyan. If you took a picture with blue light and you printed it with yellow pigment, took a picture with a green light and printed it with magenta pigment and took a picture with red light and printed it with cyan pigment and overlaid them, then you would have a color picture.
MR. LARSON: We use, it’s a compliment.
DR. HANSON: Yes, compliment. Yellow, magenta and cyan, are the compliment to red, green and blue. Now there wasn’t any technique for doing that photographically in those days. Painting and lithographic printing used the subtractive, the yellow, magenta, and cyan paints or pigments and then for many, many years there were a lot of prints made in three colors, but not photography. Now the prints that were done were called red, blue and yellow. Now, the yellow was yellow, the red was a pinkish red. They really wanted magenta, but there weren’t any pigments that were magenta, and they were sort of red. And the blue, they wanted blue-green, but there weren’t any pigments that were really blue-green, they were sort of blue, so they were called red, blue and yellow. And those are the subtractive colors that most people know about. Those terms that I use in explaining the very important invention that I made in 1943, but I’ll get to that way down the road of course. Well anyway, so the basic principles of additive and subtractive photography were known back in 1960, 1860. I keep using 19, it’s 1860.
MR. LARSON: That’s amazing that the fundamentals were known so early, but there was no way to take advantage of it.
DR. HANSON: No way to take advantage of it. And the need, the desire for color photography has been there forever. Photography just happened to be black and white. I was talking with a young lady who is writing a history of color, recently. She was saying, well, the 1920’s, the 1930’s, the climate was right. The culture was ready for color photography and I insisted that the culture was ready 1000 years ago for color; it’s just that the technology was limiting. And this whole thing has been technology limiting right up until now almost.
MR. LARSON: Yes. Incidentally, to divert for just a moment, I recently saw a book with color photographs in it of the early work in Russia on color photography, back even before 1920 and in the 1920’s. A very obscure book, but very interesting.
DR. HANSON: People have been trying to work out color photography since it was, since the basic ideas were there in the 1860’s. People have been trying. The additive process which Maxwell demonstrated first, was worked out in practice and by 1907, or ’08, the Lumiere Autochrome Process which was colored starch grains, red, green and blue were coded on the back of a plate, or on a plate, and then the emulsion was coded on that. Take a picture with that, develop it to a negative, dissolve out the negative and convert it to a positive, and project it and through the red, green, and blue starch filters you’ve got the picture just of the sort that Maxwell had illustrated. That was on the market. Now it was very slow and not very sharp, but it was color photography and it was clearly used and important.
MR. LARSON: Essentially those starch grains that acted as micro…
DR. HANSON: As micro light filters.
MR. LARSON: …filters.
DR. HANSON: That’s right. Then later in the ’20’s, maybe the late teens and the ‘20’s, [Louis] Dufay in France came out with a method of making screens, I mean lines of red, green and blue filters, so Dufaycolor used the organized lines rather than the random starch grains. Finlaycolor was a different method of making the screen plates. So there were those additive color processes in commercial use starting in 1907. In 1905, Schinzel, an Austrian who later came to Kodak for a few months in the late ’30’s, worked out the idea of having several layers of sensitive emulsion, a red, green and a blue sensitive emulsion on top of each other on the same film base. That idea wasn’t practical at the time. Then in 1912, Fischer in Germany had the idea of using color development reaction. There are certain developers that develop the silver halide to silver that will react with a coupler to form a dye. And he was able to find couplers that would give a yellow, a magenta, and a cyan dye. So he worked out the color developing process for making color pictures, but he had no way of putting the color in one layer, another color in another layer, and the other color in another layer. So he wasn’t successful in doing the job. This was 1912. Well now in 1912, when Dr. Mees came to the Kodak research laboratory, he knew that color photography was really the objective of photography, and the whole laboratory though it wasn’t devoted to that. The idea came along that it might be useful to develop the color process was investigated pretty thoroughly. There was two or three process that almost made it during the teens. Dr. [Herbert] Kalmus of Technicolor in the late teens set out to make color motion pictures. And I’m not going to go through the details of his process, but he started as most everybody did, with an additive process and if you don’t get the pictures properly superimposed, you get bad color fringes. He immediately found that and set out to make subtractive processes. He did work out a subtractive process and they made two or three, Technicolor made a couple of pictures during the ‘20’s, two color. You can take some shortcuts and make a two color process which gives some colors pretty good. It won’t reproduce all colors, but it’s a color picture, that’s a color picture anyway. They made a couple of movies two color, but they kept working on the three color process. In 1932, I’m sort of tracing them all the way up, 1932; they came out with their first three color movie, which was just…
MR. LARSON: Those movie films that were made before that were done with the two color process.
DR. HANSON: Two color, that’s right. By 1928, Kodak had gotten patents from others and had worked out a motion picture film that was three color, the lenticular film. Now that again was additive without fringes and a very unusual method of making color. The film base was lenticulated so there were lenticular lenses and there were stripes of filters, a red filter, a green filter, and a blue filter, on the lens, and those three colors would be focused by the lenticular lenses into the film and that was developed into a negative, the silver taken out and reverted to a positive and projected back through the filters, and you got a very good color picture that way. It was a very slow; it took a lot of light because the filters absorbed a lot. Took a lot of light in the projector because the filters absorbed it coming back, but anyway Kodak put that on the market in 1928. That was the beginning of color film for Kodak, but now let’s go back a little bit because the real color photography came along and was developed by a couple of musicians named [Leopold] Mannes and [Leopold] Godowsky. Their story is really something. They should be the ones sitting here instead of me, except they are both gone.
MR. LARSON: That’s, I’ve heard just a little bit about that, but I’m anxious to hear what you have to say about that.
DR. HANSON: Well they were friends in high school; both musicians and both parents were well known musicians. They got interested in color photography, and began to study it and read about it. They too started with an additive process. An additive processes had color fringes, so they weren’t going to have three or four different lenses taking the pictures. They were going to take the pictures through one lens and divide it with a mirror so there wouldn’t be any color fringes. They put on a big show in New York City, about 1917 or 1918, but they were projecting through two different lenses and they projected out of sync and they had bad color fringes. So they said no more additive color photography. We’re going to work on subtractive color photography.
MR. LARSON: But they had started…
DR. HANSON: They had started as early as the late teens.
MR. LARSON: That I had no idea.
DR. HANSON: They were working in their parents basements in New York and R.W. Woods of Johns Hopkins, a physicist, knew Dr. Mees and he knew them. And he introduced the two to Dr. Mees. Dr. Mees went down to New York and saw their work, which was very rudimentary, they weren’t getting very far, but anyway, he kept in touch with them and decided that he, the Kodak Laboratories would supply them with materials that they needed, plate coatings and various chemicals were sent to them from Kodak, at some low price, I’m sure. Finally, they were beginning to make some progress and showing some pictures that looked like maybe they had a technique of making color photography work. Then in the late ‘20’s Leslie Broker, an organic chemist in the Kodak research Laboratories who was working on sensitizing dyes to make the silver halide grain sensitive to red green and even into the infrared…
MR. LARSON: So called panchromatic…
DR. HANSON: So called panchromatic. He worked out some sensitizing dyes that could be put into emulsion and it would not wander from one layer to the next. Up until that time all the sensitizing dyes would wander so you couldn’t really coat a red sensitive, a green sensitive and then an unsensitized blue sensitive on top of each other and have them keep their sensitivities separate because the sensitivities would wander. But he worked out sensitizing dyes that would stay put and as soon as this happened, Dr. Mees, who was really a very intelligent guy, realized, “Ok, color photography can be made to work using the multilayer system now.” He invited Mannes and Godowsky to come to Rochester and work at the Kodak Research Laboratories. So they came in 1930 to Rochester and went to work. Now of course they had much of the research laboratory available to them and what could be done in the plant available to them. They asked for coatings made in the plant of two or three layers of emulsion and the plant would say they can’t make them that sort of thing. And they would insist and the plant would try and they would make multilayer coatings. They were musicians; they were talented; they worked in the dark room and they timed their experiments by whistling or humming classical music. They knew the timing of the classical music and they timed their experiments by whistling classical music. Now that is a true story. I’ve heard them, I’ve heard them.
MR. LARSON: That is an amazing story. That’s a new method of precise determination of a timed lab.
DR. HANSON: Yes, it is. Yes, it is. A lot of the people in the laboratories spoke of those musicians because they did practice their music, they gave symphonies; they took part in the musical parts of the city, but in the laboratory, they were imaginative, they weren’t scientists. They were imaginative and darn good experimenters and persistent. They tell a story that about 1932, ’33, when the Depression was really getting bad and people were getting laid off and certainly there was no expansion in research and business was bad. They were afraid that maybe they were going to be let go. So they sat down and wrote out…
[Break in video]
DR. HANSON: As I said, in the Depression, people were being let go, Mannes and Godowsky were afraid that they weren’t going to be kept in the research laboratory. So they decided to sit down and write out every step of a color process that they knew for certain how to make work.
MR. LARSON: Oh yes.
DR. HANSON: So they wrote down all of these steps and began to put them together and see if they could come out with a color process and sure enough they did. It was very complicated and only a couple of musicians would come out with something this complicated I think, but it worked. They made two color pictures that really were quite exciting. Dr. Mees looked at them and said, “We’ll go on the market with this.” And they said, “No, let’s go now for the three color process.” He said, “No, we’ll go on the market with this.” So the company started toward the market with the two color process, but they…
MR. LARSON: I had never heard of that.
DR. HANSON: Yeah, but they scurried around and put together the three color process and made it work and they did that fast enough so that the two color process never went on the market and the three color process did. In 1935, Kodachrome 16 millimeter film was put on the market and the process took, it had a something like 28 to 30 steps all of them in timing and temperature control. It took two and a half hours. It was a very complicated process. Their major contribution, the one part of it that they contributed, that wasn’t an idea from a lot of other people was depth bleach that was the way you would get the colors in the right layer and in only one layer. The sensitizing dyes in each layer stayed there, that was all right. The coupler developers which Fischer had developed back in 1912, they used and the dyes didn’t wander, but the couplers did, but they worked that out. The way they worked that out is they developed the cyan color in all three layers, first, after developing the negative image.
MR. LARSON: Yeah.
DR. HANSON: Then the rest of the silver halide they developed the cyan color in all three layers and then they would dry the film and then they had a differential depth bleach that would start bleaching slowly from the top and they could control exactly where it would stop bleaching by a stop bath. That was the secret. That was their invention that made this possible. So they would bleach out the top two layers, bleach the dye out and convert the silver back to silver halide and then wash that out. Ok, then they would develop the top two layers to magenta dye and dry the film and then slowly penetrating depth bleach would bleach out the magenta dye from the top, convert that silver back to silver halide, wash that out, and then develop that to a yellow. And that is how they got the cyan in one layer, the magenta in the next layer, and the yellow in the next layer.
MR. LARSON: I should think that almost anybody would know you certainly can’t control the diffusion of anything to a thousandth or a ten thousandth of an inch.
DR. HANSON: Exactly. You certainly would.
MR. LARSON: Anybody who knows anything would know better than to try that.
DR. HANSON: Exactly, but that’s what happened and it worked.
MR. LARSON: Remarkable.
DR. HANSON: It was remarkable. In 1935, Kodachrome 16 millimeter film was put on the market. Now at that time, Dr. Mees was head of the research laboratory; he made a bet with Mr. Lovejoy, who was the chairman of the company that within 5 years color film would be outselling the black and white film. Three years later, Mr. Lovejoy paid off that bet because within three years color film had overtaken the black and white. That just showed that everybody was ready for color when it was ready.
MR. LARSON: I can still remember the first color movie film that I saw, which happened to be one, someone had taken on an expedition of the South Seas and everyplace that was showing, I think it was on 16 millimeter, the place was sold out.
DR. HANSON: Absolutely. Well, this was the birth of modern day color photography, up until then there had been some tries and there were some commercial applications, but this was the birth of modern-day color photography. And as of now, practically all of the color processes in use by all manufacturers and by all people is based on this color development reaction, different aspects of it. But this type of chemistry is used now in practically all color photography.
MR. LARSON: There have been no real, big fundamental change.
DR. HANSON: There has been no fundamental change, two or three changes have made all the difference in the world in quality and so forth, but they really aren’t that fundamental. That is one thing that interests me about an invention, I mean an invention maybe a little improvement on something, but from a usefulness point of view, that may be tremendous. An invention maybe a completely new thought, but when you get through with it, it has no application. It doesn’t make any difference.
MR. LARSON: That’s right. That’s very true. That’s a concept that sometimes is very difficult to get across. Some scientific triumphs at least in the period of time for ten to twenty years might have no…
DR. HANSON: Might have no…
MR. LARSON: …difference.
DR. HANSON: …make no difference and yet the idea and the thought leading up to it is just a big a jump.
MR. LARSON: Right. Well, very good.
DR. HANSON: This is when I came into the picture. That film was on the market and I was asked to come and work on 35 millimeter, 35 for the Leica and Retina cameras, for amateur slides. So I entered that program in 1936. When I went into that I was asked to also, sort of as a side line, to write a series of articles on the history of the science of photography, which fortunately forced me to study all of the literature in the science of photography which I had done before. That was a good thing. Somebody asked me to do that, I did it and it really was a very important thing because it forced me to learn what was known about photography. So I became interested in the science and I worked in the science of it as well as the practice of the color photography. So we went to work to apply this complicated process to 35 millimeter for the amateur. That took a lot of detail doing, but no major changes were made. We also, the group that I was in, had the responsibility of looking ahead and planning to adapt this process to the motion picture industry. Now Technicolor had a patent on the multilayer films. Mr. Trolland of Technicolor in 1917, 1918, applied for a patent on multilayer sensitivities and that patent was granted in 1931. So it stayed enforced until 1948. Kodak of course had to have a license under that patent and we could not have manufactured and sell motion picture and color film using that patent to anybody. But we still we went right to work on trying to apply the Kodachrome process to the motion picture industry, through Technicolor and eventually to others. So that was our job. Now a part of that job, part of the use of color film in the motion picture field is you have a camera negative, you take the picture, or with camera film, you take the picture, you make hundreds of prints to go around into the theaters. You have to have some intermediate stages to put in dissolves and fades and embellishments, that sort of thing. So you have to make copy after copy after copy after copy. Making a copy of Kodachrome to another Kodachrome you don’t get such a good picture. Now, a Kodachrome slide is a beautiful picture, but you make a copy of it, it’s not so good. You make a copy of that and it’s pretty poor. So one of my objectives right from the beginning was to learn how you make copies of color pictures. I thought that, I worked that for 5 or 6 years and I’ll come to that later on. While we worked out the amateur film, we were also working on applying it to motion picture professional and working on different techniques of making copies and everything we could think of we would try. As we went to market with Kodachrome 35 millimeter film for slides, we had production charts on the wall and we had them listed as the Leica Program, now the Leica was an important 35 millimeter camera at the time. In fact, 35 millimeter amateur cameras were relatively new at that time. Most amateur photography was with big roll film cameras and the 35 millimeter camera had just come into use. Well, we had listed on the board the Leica Program. Well, some management people came down and saw that and changed it to the Retina Program which is the Kodak 35 millimeter camera. That is just a little aside that was amusing there. But, ok, so, we got the 35 millimeter on the market and immediately began to try to improve things. The research was never cut back. Research in color photography was always increased. We knew that color was wanted across the board so as we can learn to do it, we’ll do it. But first of all we had to simplify that process. That process was 30 steps, two and a half hours, was too complicated. So a couple of inventions were made so that the process was simplified a great deal by 1938. Instead of having the depth penetrating bleach, it was found possible that after you develop the film to a negative, you could expose with a red light the residual emulsion that was left and expose only the red sensitive layer then you could develop that in the cyan color developer then you could expose with blue light and expose only the blue sensitive layer because there was a yellow sensitive layer which kept the blue light from getting into the middle and develop that with the yellow developer and then fog, or expose with green light the middle layer develop that with magenta so that you have the three color developers that you did by exposure and not the depth bleach. It was a much simpler process. There weren’t nearly so many steps. And it was much easier to control. So the process was converted to that method in 1938. Now there had been a number of minor changes in timing and it was cut down to 18 minutes, the temperature has been raised, and a lot of things have been improved since then, but basically the process is the same now as it was in 1938.
MR. LARSON: Well, that is a wonderful explanation of these very fundamental developments that have lasted to…
DR. HANSON: They have lasted to this day. Now we immediately set out to apply this process to sheet film for commercial use. We went up to, I guess, 14 by 17 sheets was the biggest that we did, but we were successful in developing, adapting a machine that would operate this process and adapting the Kodachrome process to commercial use and Kodachrome sheet film was very important in the commercial field and advertising field for a number of years. Just as that was beginning, Bradford Washburn who was, oh let’s see, what was he? He was in charge of the Harvard School of Geographic Exploration, and later became the head of the Boston Museum of Science. He was a photographer and he wanted to take a lot of pictures of Mount Everest and all over Alaska, not Everest, I’m mean McKinley, sorry, and all through Alaska. One of the members of the research laboratory at Rochester got him some Kodachrome sheet film and he took a lot of pictures. He was told, now this is color film, you don’t use a filter because that is just for black and white film for effects. Color film you don’t use a filter. Well actually, he was using film that was balanced for artificial light and he was taking it in daylight. He should have been using a filter actually. (Laughter) So the film came back to us for processing and here the first batch of it processed and it was obvious what had happened. So I was given the job of completely working out a new process to use to try to get that improperly exposed film to come out looking right. I spent weeks working on a process for that, but got one that worked all right. So we got some excellent aerial shots that Bradford had taken on the wrong kind of film.
MR. LARSON: I think all of us at some point put the daylight film or artificial film, made a mistake or forgotten; you know what the effect is.
DR. HANSON: Yes, well it was possible to work out a special process to handle that. So that was done. We immediately set out to adapt the Kodachrome process to roll film. Now roll film was the standard film that all amateurs used, and all amateurs wanted prints and Kodachrome to this point only made slides. So we set out to adapt it to roll film and to paper and to make prints from the roll film to the paper. Now here again the problem with making a print from a Kodachrome was with us. Techniques called masking had been worked out and helped. I’m not going to go into all of the details of how masking works, but anyway a mask, a negative image, in contact with a positive image, when you print it. You can devise a mask that will give an improved quality. So…
MR. LARSON: Commercial people in printing use that a lot.
DR. HANSON: People in commercial printing use to use masks all the time. I don’t mean mask around the edges of the picture, you know, a negative image on a positive image. We devised a method of adding a mask to the Kodachrome roll film, a silver image mask, and that added about 15 steps to the process. That put it back about as complicated as it had been to start with. But it worked almost and the quality of the pictures was improved by it. Another problem, the Kodachrome coated on paper gave model. The Kodachrome is the reversal process. You use everything that is there. You develop the negative and dissolve it away and then you use all that is left in the emulsion to make the picture. Paper had little irregularities and so there was model. For two years we worked on that problem and I used to go to meetings in the plant where they made paper and they made coatings and every two weeks we had a meeting and somebody would report that model had been improved. After two years, the model was essentially the same as it was to start with.
MR. LARSON: One of those intractable problems.
DR. HANSON: One of those intractable problems, but I went back and reviewed all of the minutes of the meetings later and every meeting it was reported improved, but it hadn’t changed a darn bit. Well anyway, it probably was fairly acceptable and we were already to go on the market with this very complicated roll film process and this paper with model when the Kodacolor process came along. I guess I say we were sort of saved from ourselves. Now let me tell you about the Kodacolor process. As I have said Kodachrome, you go through the three color developers and each one of them puts one color in. Earlier couplers had been invented which you could put the coupler itself in the emulsion and it would stay in that layer. You could put a cyan-forming coupler in the red sensitive layer and you could put a magenta-forming coupler in the green sensitive layer and a yellow-forming coupler in the blue sensitive layer. Now making such couplers was complicated chemistry and designing them was sort of complicated. Kodak had been trying to design such couplers. In fact, people had been trying to design such couplers since Fisher back in 1912. In the middle ‘30’s, Willmans at Agfa in Germany did design such couplers and Agfa came out with a color negative process, not a reversal process that made the color negative in the late 1930’s. About the same time, Kodak was working on couplers that you could put in the emulsion. And Vitum and Jelly a couple of people in the research laboratory came up with the idea that you could make a coupler with a ballast, a big molecule on it, which you could dissolve in an oil, disperse the oil in the gelatin emulsion and that the coupler would react. The developer would go into that oil and react to form the dye and sure enough that worked. The couplers that Agfa had worked out had a big ballast too. They also had a solubilizing group so that it would dissolve right in the emulsion rather than being put into oil. That turned out to be a surfactant. Just by nature that was a surfactant, it made those things very difficult to manage. So in the long run by chance the protected coupler process dissolved in the oil had proved to be the process that all of the companies use. That is just one of those things that worked out that way.
MR. LARSON: Oh, yes.
DR. HANSON: That was invented, worked out about 1939, 1940, and just before we were ready to go on the market with Kodachrome roll film and paper, this process came along and so the whole program I had been working on night and day for two years, was scratched. Other people had been working on the Kodacolor so that moved along very fast and Kodacolor roll film was put on the market in 1941. In the meantime, I went back to working on Kodachrome. I was at that time, mostly a Kodachrome person, not Kodacolor, and I went back to working on Kodachrome for application in the motion picture industry and though we couldn’t sell it generally, we could sell it to Technicolor so we worked out a Kodachrome process that, film with the characteristics properly adapted to the motion picture use and Technicolor began to use that film in 1942, I think, and used that film for a little while and made a few pictures with it. We also decided to begin to make prints from the Kodachrome slides. By now Kodachrome slides had gotten to be pretty popular. There were a lot of them out there. So we worked out instead of a Kodachrome process on paper, we worked out a Kodachrome on white pigmented support, which was smooth and you could use the reversal process without the model. So we put on the market there in the research laboratory the mini color prints which were made from Kodachrome slides and we did the production of mini color prints for many years. And that process had some unique features. It took a little bit to work out a process of that sort but it was no big change in procedure, or in science. All of this time, the problem with making these prints and making the quality with masking, or without masking was in my mind and everything that came to mind was being tried. Finally, in 1943, lying in bed, I thought of an idea. Supposing that coupler, and this applied to Kodacolor, not Kodachrome, supposing that coupler, like the cyan coupler which is going to form a cyan dye, supposing that coupler itself is colored yellow or orange, when the cyan is formed the yellow or orange will be destroyed and so you have a cyan negative image, and a yellow or orange positive image and that orange, I will call it, will just cancel out the undesired blue and green absorption of the cyan dye, and so you will essentially have a perfect cyan dye. Now the magenta dyes absorb some blue, and are actually reddish rather than pure magenta. So that magenta color is going to be yellow and the yellow positive will just cancel that blue absorption of the magenta dye so that you essentially have a perfect magenta dye. Now already, yellow dyes don’t absorb green and red so essentially the yellow is perfect. So with colored couplers of this sort, you could make a copy that would be exactly like the original, or exactly the positive from a negative, but still you would have any of the color defects caused by the improper dyes. So…
MR. LARSON: That is a remarkable thought.
DR. HANSON: So, lying in bed I thought of that.
MR. LARSON: That is a very amazing sort of flash that you had.
DR. HANSON: It was a flash. I had been working on the problem and thinking about it for years, and reading about it, but that idea came lying in bed one night. I immediately went in the next morning and wrote a half a page invention report and went to one of the guys, Vitum who had helped invent the Kodacolor process, and I explained the idea. He says, “You know, I think I got a coupler on the shelf here that’s already yellow, maybe this will work that way,” and we tried it. And the very first try, it worked sort of. So we could see that the idea was working. Immediately, several of us got excited about it and began to follow up and try to make that work. One month later, I joined the Manhattan Project and left color photography for a couple of years. Right at that point when I had that idea, I left for two years. Let’s break now.
MR. LARSON: All right.
[Break in video]
DR. HANSON: I think I’ll sort of enter a diversion and talk a little about the science, basic science of photography. The light sensitivity and the development process. The photography is based on using a material that reacts to light. But that reaction has to be magnified a great deal. The development process in the photographic process amplifies the effective exposure by millions of times. Now a lot of materials are sensitive to light. But there are not many, in fact maybe none that can be, react to such a small quantity of light like silver halide and have that small quantity magnified in such a large amount. Now many materials have been investigated, polymers and all sorts of chemicals, but it turns out that silver halide is unique. This has been learned as we have gone along and people are still learning about it. But, way back, everything was empirical, making the silver halide grains, people tried things, they would find that they were more sensitive than the other. Then in the 1920’s Dr. Shepard in the Kodak Research Laboratories began to study gelatin and its effects on the grains that were made and it was found out that gelatin has some sulfur compounds in it. That cows eat mustards in the fields and that puts some sulfur compounds.
MR. LARSON: Oh yes.
DR. HANSON: And these sulfur compounds sensitize the silver halide grains and make them much more sensitive than they would be otherwise. They also can go too far and fog the silver halide grains. And that was one of the problems that George Eastman had back in 1902, 1882, ‘83, when his plates were going bad, it was a bad batch of gelatin.
MR. LARSON: Oh yes.
DR. HANSON: But it was in the 1920’s that that became understood, the role of gelatin and the role of sulfur in sensitizing the silver halide emulsion.
MR. LARSON: That poses a real problem in control by being dependent on how much your cows eat of the mustard.
DR. HANSON: Exactly. You know it was a long time before it was possible to thoroughly purify the gelatin and eliminate those things and then add the amount of the sulfur compounds that you want add. Of course, that’s the way its done now, but that is only a recent development that that has happened. Then in the 1930’s, people began to study the mechanism of the formation of the image. Webb at Kodak, Ernie Mott, Bristol England, later, Mitchell, John Mitchell, also in England who moved to the University of Virginia, studied the mechanism of the formation of the image and how one or two photons could make a stable speck in the mechanism of silver ions moving through the crystal and then trapping electrons and then that sort of making a speck that the next silver ion released by light would move to the next speck. That sort of understanding of the sort of electronic nature of the silver halide crystal and its behavior began to clarify the process and made it possible by scientific means to work out means of improving the speed and making those specks more stable, making them more sensitive to the development, the mechanism of how the developer could act on that speck. I mean that developing agent has to be a reducing agent that will reduce the whole silver halide grain eventually, but making it reduce just the exposed grains with a very small speck and not the other ones is part of the, for a while, it was entirely empirical, but through the ‘30’s and ‘40’s, those things began to be studied very quantitatively so that as of now, speeds of the emulsion are in the thousands, when they were in the one’s and two’s back in those days. So all of those things are a very important part of the development of color photography, or any other photography. And many research laboratories, Agfa, the Japanese have made important contributions, but the Kodak Research Laboratory was sort of the center of the development of this science for many years. In 1936, a member of the Agfa research laboratories discovered gold sensitizing. You could sensitize emulsions with gold that increases, a little speck of gold, that increases the sensitivity by a factor of two or three times, which is very important. I can remember in the late 1930’s when Agfa came out with a motion picture film, this was black and white, which was faster than the Kodak film. You could also make faster films by having bigger grains and making it grainy, so having speed grain is the factor that’s important. They came out with a film that was less grainy than the Kodak film and was faster. Now there was pandemonium in the Kodak research laboratory.
MR. LARSON: Oh yes. I imagine that was a real emergency.
DR. HANSON: Everybody involved had to go to work on what was it that they were doing and how could we do as well or better. Within a short time, gold sensitizing was discovered independently in the Kodak research laboratory and used. Now, Agfa did not patent it.
MR. LARSON: They tried to keep it a secret.
DR. HANSON: They tried to keep it a secret, and Kodak later did patent it. Now, there were variations that were patent.
MR. LARSON: Oh sure.
DR. HANSON: But Kodak did patent it, but there was a lot of scurrying around in those days to learn how to sensitize emulsions that way. Now there have been a few other major contributions to emulsion technology that gives speed grain increase, so that as I say the speed has increased many times since 1930. That was an interesting activity. Now another part of speed of the emulsion is spectrosensitizing. Organic dyes are absorbed to the grains to make them sensitive to green, and red, and even infrared. Now the mechanism of the transfer of the energy from the, that’s absorbed from the dye into the grain has been a very important study and is a fascinating study. I mean, many dyes will not transfer that image. In fact, many dyes are desensitizing dyes. You put them in and they desensitize, but learning how to make one photon of absorbed energy from a dye transfer and give one atom of silver into grain took a lot of doing. And again, that study goes on in all of the research laboratories in photography. Well, let’s get back to sort of the chronology of the development of the various films.
MR. LARSON: That clarified a good deal of the history of the development of the science and technology of photography.
DR. HANSON: We were about 1941, ’42, no we were up to ’43 when I left. That’s right when I left. Well, during the war, the Kodacolor process which had gone on the market as roll film was adapted for the use in aerial photography. Now people in the Army had come to Dr. Mees at Kodak and said, “We have got to have Kodachrome for aerial photography. You got to teach us how to process it in a truck”, and Dr. Mees said, “There was absolutely no way that you could do Kodachrome that way.” He said, “We got this other process; we’d have to go to work real fast to work out a film using that process.” So Kodacolor aero later called Autochrome aero was worked out and was used during the war.
MR. LARSON: For aerial…
DR. HANSON: For aerial reconnaissance, yes. And also as part of that use, infrared sensitive film was worked out too. That gives false color. If one of the three colors is infrared sensitive then you get quite distorted colors and that becomes a camouflage detection film and that was used for camouflage detection.
MR. LARSON: Oh, yes.
DR. HANSON: Fairly successfully, yeah. Well, when I got back to Rochester in 1945, the Kodacolor aero film was in use and had been developed. Autochrome film which was that same process being applied to professional use, sheet film Autochrome was just about ready to go on the market. The colored couplers which I had thought of just before leaving, had been worked out and were just about ready to go in the product on the market. A lot of work had gone on there, designing the couplers themselves, having them have just the right color. I mean I talked about the cyan coupler being yellow or orange. Well it had to be exactly the right tinge of orange. And it had to have the right intensity. If it were too orange, it wouldn’t exactly match what we wanted it to match. All of those things had to be worked out. The reactivity of the couplers with the developers, all of those things had to be worked out too, but they had been worked out. A lot of work had gone on and it was just about ready to go on the market. I’m very pleased with that naturally. One other thing that had happened too, Kodachrome developers are toxic, I mean allergenic. If you get color developers on you, the ones that were classically known, you get a skin rash. Dr. Mees had decided that no way we would sell for anyone else to use the Kodachrome process or any other process using those developers. We have got to have a non-toxic developer, even for the military. So the chemist, Arnold Weisberger, had been working on making developers and he invented, or worked out the formula for a new color developer that was non-allergenic. And so just about the time I got back to Kodak, that was being worked into the system and in fact, it had been used in the aerial film. The Army use was the non-toxic developer. But let me talk about Arnold Weisberger a minute because he is a well-known chemist who came to Kodak in 1936. He had, he was from Germany and left Germany to go to England in the early ‘30’s, as a result of Hitler.
MR. LARSON: Oh, yes.
DR. HANSON: And he became one of the well-known chemists in the world. He wrote books and edited many books, but he came to Kodak and he began to work on compounds for color photography. So I met him in the middle ‘30’s. He remembers this story, which I should have told a little earlier, but I don’t remember this story, but he was making magenta couplers for us when we were working out the Kodachrome process for 35 millimeter film. The magenta coupler was a brown, powdery stuff, very impure chemical. He brought us over a sample of nice yellow, clean crystals. He had really made a batch of that coupler that was just as pure as could be. We tried it. He tells the story that he came over to find out what the result was. And so I said, “Arnold, you sit down right here.” I showed him the result and we got about 80 per cent dye with a pure compound as we had gotten, always gotten with the impure compound. (Laughter) And we found reasons for that, but that set back the purity of compounds for a long time, I’ll tell you.
MR. LARSON: That’s amazing how some of these things work just the opposite.
DR. HANSON: Just the opposite, yes. Well, of course by the time the compounds were put into the emulsion, not in the developer, they had to be very, very pure. So the purity of compounds did become very important, but that set it back for the Kodachrome process for quite a while. Well, gee, where was I? Well, as I said, the color couplers had been worked out and were in a film just about ready to go on the market in 1946, and in fact, in 1947, Autocolor seed film went on the market. That was a professional film using the color couplers, the first film using the color couplers. It used the non-toxic developer, it was for use by professionals and they were to make prints using the dye transfer process. Now Panmatrix film, a matrix film which you can expose with red, green and blue light, through the color negative, the Autocolor negative then make a dye transfer print. So commercial photography now had been simplified and prints could be made by professionals. At this time, we were still looking for new applications, looking for new science. I and my boss, Mr. Ralph Evans, were very interested in the science of color and applying that to color photography. We studied colorimatry, we decided to write a book on the principals of color photography, which we did in fact and was published in 1951 or ‘52, and began to work out all the theories that we could. Actually, I went to a Photokena meeting of the international photographic society, I guess this was actually in the 1950‘s and gave a paper on the theory of color photography. As a matter of fact, it was the paper for the entire audience and I didn’t know it was going to be that until I got there. I was scared to death. I got up in front of the audience as a young man and then gave this paper on the theory of color photography, but that was interesting keeping all of that theoretical work going along with the practical. We still were trying awfully hard to work out a film for motion picture use and now that the Kodacolor process had been invented, we could use that to make a negative, if that was the right thing. Well Kodacolor, Autocolor at the time, was much too grainy, much, not nearly sharp enough for motion picture use. All the uses of film then were big sheets or the roll film several inches wide, and it was just no way that the film was good enough for 35 millimeter, but we kept trying. We learned how to coat the film, thinner, and thinner, and thinner. Now that was all done in the manufacturing divisions but not all of it, but anyway, they were learning all the time how to coat thinner and thinner, and that made sharper pictures. The chemists were learning how to make the couplers more soluble so you didn’t have to have so much coupler solvent, trying to make the couplers more active, so we put fewer and fewer chemicals in the coatings. I mean everything you could do to improve sharpness was being done. Another invention was made about that time. It was discovered that there were sensitizing dyes that not only wouldn’t wander from one layer to the next, but wouldn’t wander from one grain to the next. If you put them in an emulsion, it would get on the grain, you could mix another emulsion together and have a mixed grain process where the green sensitive grains staying green sensitive and the red sensitive grains. So, there was a chance to make Kodachrome in one or two layers. We put a lot of effort into working out a Kodachrome film in one layer. For motion picture use, if that was the release print film where you make a lot of copies, the cost of that film makes a lot of difference. So we would visualize we’ll have a color negative film and we’ll print a positive from that, both of these with color couplers so that the color would come out all right, and then we would print that onto this monolayer film. It was a little complicated to process, but professionals at motion picture laboratories could do it and that would be a cheap motion picture film. So we worked for years on that program. Well first of all making the color negative, it wasn’t nearly sharp enough, but finally we had gotten some improvements in sharpness and some improvements with graininess. We decided working on roll film for the amateur, and we decided let’s make some motion pictures and see what it looks like. So we made some motion pictures, cut some of that film up for motion pictures and made motion pictures only about 1947 or ‘48, and printed them on a positive film that we were working on. And, boy, they were beautiful for just general quality. They weren’t very sharp and they were too grainy, but the general effect was really something. We showed these to top management and they said, “Look you got to make this work. That’s good. We want that.” So, we went to work to try to improve the graininess and the sharpness. I can remember to this day, another idea that popped out looking at some pictures over a white view box, an idea as to how to fix the graininess. It doesn’t make sense to people that weren’t really steeped in what was going on but the idea that the cyan layers, instead of coating it in one layer you coat it in two, and the magenta layer, instead of coating it in one layer you coat it in two. And you structure those layers right, it would improve graininess significantly. I just knew that would be the case and we tried it, and boy, it really did. Now I’m not going to explain why that works, but anyway, it did. It really worked. It upset everything else, it took a lot of doing to really get that worked out so you could really get nice pictures with it, but it worked and there we had a motion picture negative film. So the company decided well we’ll sell that motion picture negative, and we’ve got a positive we can sell, too expensive, we were still working on monolayer for the positive, too expensive, but we’ll sell this positive. This was about 1950, ’51 now, and we don’t know how people are going to make intermediates, they’ll have to figure that out. We’ll come along someday and have films that will make the intermediates, but we got to sell these films. So that was started. “The Royal Journey”, the Queen of England was traveling through Canada that was the first picture made on this combination of films. The Eastman color negative and the Eastman color print film, with no intermediates. No other picture was ever made like that, but that one was and it was quite successful. We were still working on this monolayer. That was the way to make motion picture positive, it just had to be. It was the cheapest film we could imagine. Another invention came along which completely negated that, and it was also an unbelievable invention. The multilayer film has many layers coated on it. You coat a layer; you set it up with gelatin liquid, a sort of gooey liquid, you set it up, maybe dry it, coat another layer on it, set it up maybe or maybe not dry it, but you got to set it up, and then coat another one on it. Somebody came up with the idea of, ok, let’s coat all of these different emulsions at the same time. We’ll have ourselves a little hopper out of this slit will come one emulsion, out of this slit will come an emulsion, and out of this slit will come an emulsion. They’ll roll right over each other; they’ll stay separate go down on the film base, coat them and dry them, and then you’ve got the coating. There was no way that was going to work, but it did.
MR. LARSON: After all that work, they would be mixed together.
DR. HANSON: They would all mix together. Well as a matter of fact, they stayed clean as a whistle. They do not mix. Our coating hoppers, which people called Joe Hoppers, coat of many colors, but there are six layer coating hoppers in use today. Now of course making motion picture positive with just one coating operation, you got to make the three or four emulsions anyway if you mix them and coat them you might as well feed them separately and coat them. That completely negated any need for monolayer and since it was pretty tough, that program was canceled out of a month. So that was the second big program that I was working on that just got canceled. But they got canceled by something better. They didn’t fail, they just got improved upon and something else displaced them. A lot of things happen like that, and something better comes along.
MR. LARSON: Oh, yes. Remarkable story.
DR. HANSON: So, that made it possible to have a motion picture process that was economically feasible, so we did go to work and work out the intermediate films. First of all, we made black and white separation positives. Then we made a duplicate negative. You coat those three black and white positives onto another negative and then you would print that negative onto the print film. That was commercially used for two or three years. Then we learned how to make an intermediate film with good enough characteristics so we could have the color intermediate positive put right back onto itself to make a color intermediate negative and then print that onto the motion picture film. Now that is the film that is in use today. Many improvements along the way, but that sort of film is in use to this day. We’ll all this time we were still trying to improve amateur film and we introduced the colored couplers into the Kodacolor roll film. Just as we were about to get that ready for the market, we had a problem with the government. Kodak was a monopoly we could not control the processing of Kodachrome ourselves. We couldn’t sell Kodachrome film with the processing price attached to the film. We were the only ones that could process it and we always looked at it as the processing was a part of the manufacturing of the picture. The process was much too complicated for the general public to do, but the Justice Department says, you can no longer sell the film with the processing included. So we quick decided well, we don’t really want to disperse the Kodachrome processing. Maybe one or two big people could do it, but let’s work out an Autochrome film which was a lot easier to process for 35 millimeter 35, for slides, that the general public can process. So we very quickly went to work and worked out a 35 millimeter Autochrome film. Now at that time, even though we had the color negative that was good enough for motion picture, Autochrome had not been thought to be good enough for 35 millimeter use. Actochrome was still big sheets or roll film, but applying all of the coating technology and the chemical technology to Autochrome it was possible to work out a slide, a 35 millimeter slide film with Autochrome. So in 1955, when the Kodak Consent Decree was signed and we gave up, we stopped selling Kodachrome film with the processing charges attached, we made Kodachrome process available to people, but we thought Autochrome is what they should do, and we also thought that Kodacolor is what was going to grow anyway. So this color coupler Kodacolor was worked out using the non-toxic developer instead of the toxic developer that had been used so that it could be processed commercially. In 1955, with that Consent Decree, color photography sort of became general. It was processed all over the place, Kodacolor prints were made all over the place, and motion picture film was available, so by 1955, I think you would say color photography was here. One of the problems was in making prints and they get exposed to light all the time and to the atmosphere is that the dyes in color photography are not the most stable things in the world, or weren’t at one time. So dye stability was one of the big problems that was studied all the way going back to the 1940’s people were beginning to learn about it. It took a lot of learning and empirical studyes before you knew which direction to take. One of the stories that the Kodak dye chemists tell that is amusing about dye stability is you don’t want to wait 25 years to see if a dye is going to fade in 25 years, you have to have accelerated tests. So, how do you define an accelerated test that will give you the right answer? Just take for example, the egg. Now, you put the egg in the refrigerator and it’s good for months; you put the egg out in the sun and in a few weeks you’ve got a rotten egg; put the egg in an incubator and in two or three weeks you got a chicken. I left out put it in boiling water and in a couple minutes, you got a hardboiled egg. So how do you design the test to, the rapid test to tell what is going to happen to an egg. Same thing to dyes some dyes are oxidized to destroy themselves; some dyes are reduced; some of them need moisture for stability; some of them are destroyed in the presence of moisture. So you’ve got to work out all these things and work out all these tests before you can really develop perfectly stable dyes. Now, this work is going on, but as of now, the dyes are almost achievably stable and color prints are quite stable and color motion pictures are quite stable.
MR. LARSON: Well that is a tremendous advance…
DR. HANSON: A tremendous advance in 30 years.
MR. LARSON: Early color prints really have difficulty…
DR. HANSON: Well the early Kodachrome slides, before 1938 are all gone now, they just faded. Now the Kodachrome slides made in 1938 on, in the dark, are essentially stable. I have some made in 1940 that are just kept in an album. They are just as good now as they were then. In the light those dyes fade some. A tremendous amount of chemical research has gone on in that study. Something like 30,000, 40,000 couplers have been made studying color and stability. Oh, that’s another point that I haven’t…
MR. LARSON: That’s a tremendous effort.
DR. HANSON: A tremendous effort, and millions of man hours of work. Designing a magenta which is exactly the right type of magenta, there are all sorts of magentas, and thousands of them have been made to get the right dye, exactly the right color. The dye, the coupler has to be reactive with the developer and so you have to learn chemically what sort of structures are reactive and what sort of structure isn’t. The chemical research that has gone just into this area is huge. Ok, well that sort of brings us up the point where color photography is here. It’s available to everybody, it isn’t that convenient yet, the speed of the films is not that great, 24, 16, or something. So and loading a camera is complicated. So, we set out to make it simpler. From here on, I think the quality is here, generally, ok, let’s make it easy, simple so people can use it. Increasing the speed, well I’ve told you a little bit about doing that. Well, all of that has been applied to photography. Increasing the sharpness by mechanical and chemical methods that work has gone on. Now, 1963, the cartridge camera was worked out. The Instamatic camera, Kodak began to sell that in 1963. Now that had the cartridge with the film in it which you can load right in the camera. Now actually, that is saying that when you take the picture, the cartridge is part of the camera. So the mechanics of seating that film, having the cartridge itself seat properly in the camera and the film sit properly in that cartridge so that it’s in the proper focal plane. That takes a lot more doing than people stop to think about just putting a cartridge in a camera, but all of those things had to be done. But also the design of that system was such that the film speed had to be twice what we had ever been able to make it before. That took just a lot of steady work, using all that was learned, and that was successful. One of the things about the Kodak business techniques at the time that amazes me is that in 1963, that Instamatic camera, the camera with the cartridge, easy loading camera was put on the market. That camera and film were in warehouses ready to go all over the world, so it was announced and available for marketing all over the world all at the same time. The stock analysts and the advertising people except those we want to, I mean all of it was kept a secret. And that was amazing.
MR. LARSON: Fascinating there that that whole new development which was…
DR. HANSON: And it was put in place with the competition and the advertising people not knowing it was there. These days products are announced about a year before they are out there…
MR. LARSON: That’s right.
DR. HANSON: …from almost everybody, but…
MR. LARSON: Right, when you try to go buy it, it’s not available.
DR. HANSON: It’s not available, but that one was really done very well that way. Let’s talk a little bit about the overall applications of photography.
MR. LARSON: Ah, yes.
DR. HANSON: The major thing is the pictorial application, of course.
MR. LARSON: That’s right. You mentioned before the fantastic contribution it made to the application, the x-ray.
DR. HANSON: The x-ray as early as 1896, film was applied to x-ray. 1928, RecordEc, recording checks and recording other objects and documents, but that started in 1928. Now the characteristics of that film are very different form the characteristics of the film for pictorial use. So a RecordEc film was worked out in 1928. 1929 sound on film. Sound is recorded in waves, or in dots, and the characteristics for a film on that are different from any other, but sound film was worked out in 1929. Codalift film for graphic arts, for making half tone screens that film has exceedingly high contrasts and no toe, no credition down here; it is almost straight down to white.
MR. LARSON: Black or white.
DR. HANSON: Black or white. That film was worked out. It took a special, very sensitive sort of process to make that happen. It’s only in recent years, in fact, almost recent months, that a very stable reproducible process can make that sort of a characteristic in a film, but that now is available. Reconnaissance film, I’ve mentioned that, the V-mail film during the war, RecordEc, sort of the same sort of film for that. The computer output microfilmer. Kodak worked out a very neat method of exposing film using lasers. The lasers emodulated by a gusto-optic device to print the digits. So a computer output microfilm with laser exposure with gusto-optic control is on the market now. I was always amused by that. Nuclear tracks, nuclear tracks, nissans, all sorts of rays make tracks in photographic emulsions, and let’s see, it was Cecil Powell in 1940 discovered the nissan in a photographic emulsion, the track in a photographic emulsion. And he got the Nobel Prize in 1950 for that. That was the fact that it was photography had nothing to do with his prize, but it was photographic emulsion that he was using, or the photographic emulsion.
MR. LARSON: The characteristics film had to be done.
DR. HANSON: That’s right. Astronomical uses. Now that is a special use. The films are exposed for 4 to 6 hours and there is a lot of haze and background so the characteristic that has to be put into astronomical films has to be very carefully understood and designed. An interesting concept called detective quantive efficiency is very important in astronomical films. A study of that characteristic of films and how you maximize that rather than some other characteristic is what you do when you design an astronomical film. Another aspect of it is exposing for 6 hours. Now photographic film, there is a law called the Reciprocity Law, exposure time and intensity are interchangeable. If you double the intensity of the light, in half the time you got the overall effect. Well, in fact, it doesn’t work that way. There is a reciprocity failure and the mechanism of it is now known pretty well, but a film that is going to be used for astronomy where the exposure is 4 hours has to be designed very differently where you’re going to expose it for a thousandth of a second. All of those things have to be learned and used. There was a film called bi-mat that had a great future at Kodak people thought which was, all the chemicals were put into a layer and they were put in contact with the exposed film, they’d developed it and sort of drew out of there all the excess and you came away with a negative. Very much like the Polaroid process which I will talk about in a little while perhaps, but this bi-mat film never did develop an application until the lunar orbiter came along. Back in the early ‘60’s when they were taking pictures of the moon prior to landing on the moon, they put the lunar orbiter up there with bi-mat film in it which could be developed on the spot and then those images radioed down and so that was used on the lunar orbiter.
MR. LARSON: That’s very interesting.
DR. HANSON: Ok, gee, where are we?
MR. LARSON: Well, we…
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DR. HANSON: Along about this time, I got moved out of color photography for a little while. I became the assistant director of research and the whole color photography activity, well most of it, was sort of taken out from my responsibility and I was given responsibility for the physics and chemistry and all the new things and I was sort of, even though I had been working pretty much on practical things, I was sort of a theoretical person and interested in the new things and so I got involved in physics and magnetic tape and electronics and chemistry, basic chemistry and that sort of thing. But I kept involved in, my involvement in color photography never the less. One of the things that I was very excited about for a while, turned out to be super 8 millimeter. Now 8 millimeter film which was the major amateur film is cut from 16 millimeter film, it has perforation holes, big holes that it’s pulled down with as it moves through and a lot of space between the pictures and there was a lot of waste on it. I had worked awfully hard to improve the sharpness of films and I figured, gee, if we just used more of that space that would improve the sharpness of the picture a lot more than any change in the film I can imagine. And so I began to promote the idea of using little bits of perforations and smaller intermediate lines and make the picture just as big as you possibly can. People said you’re not going to change the format at this time, but anyway, we went with it and we finally sold it to management and we came out with super 8 millimeter film, which was a lot sharper and a lot better than any 8 millimeter had been before. It took a lot of mechanical doing; it was all mechanical of course. But that did get done anyway.
MR. LARSON: I can remember how much sharper and more satisfactory it was.
DR. HANSON: Much sharper pictures. One of the fellows in the laboratories working on the super 8 was interested in amateur photography in general, amateur movie photography. He was just doing all sorts of experiments and he wanted to, film speed was improving. We were using higher speed films in 8 millimeter. Now the 8 millimeter lens is a pretty small thing. If you have a high speed film and you close down the aperture of the lens you run into a refraction limitation and you begin to lose sharpness. So he wanted to see if he could improve that. So he tried to get a shutter in the camera, the movie camera, there is a shutter that goes around and blocks the light when the film is moving. And so he wanted to get a shutter that he could close down and cut down the exposure by cutting the shutter rather than by closing the aperture of the lens so he wouldn’t lose the sharpness. Well he ran into a very strange phenomenon. As he closed the shutter down to a very small angle so the exposure was very short, he got very jumpy motion. Anything in movement would be so sharp that he would get very jumpy motion.
MR. LARSON: Oh yes.
DR. HANSON: And that was not good. Well he immediately began to think the other way. Ok, let’s open up the shutter and see what happens and he opened up the shutter so something like 330 degrees, it has to be a very fast turning shutter, but anyway, it could be done. He got very smooth action and that also made him think now that is also giving me two or three times the exposure that I use to get, maybe I can begin to take pictures without any lights. Now the lights for motion pictures at that time were a nascent. He began to think of available light. He got himself a camera with about a 330 degree shutter and got some of the highest speed Autochrome slit 8 millimeter and began to take pictures and sure enough he could take pictures in a room like this perfectly well exposed. And in a dark laminated bar, and they weren’t quite exposed enough. Then he realized the concepts called TEMS, T-E-M-S, terminal exposure modulated scene. Now the eye adapts to light.
MR. LARSON: Oh yes.
DR. HANSON: And everything looks about the same brightness until you get down to a certain level. And then at that level as the light goes down you notice it gets darker and darker and darker. That level of illumination is about 7 foot-candles. Anything below 7 foot-candles looks dark to the eye. That is the way the picture should look. I mean you don’t want to take a picture in a dark bar and have it come out looking like it was bright daylight, or you don’t want to take a picture under moonlight and have it come out looking like it was broad daylight, which you could do with a longer exposure. So that terminal exposure modulated scene of 7 foot-candles sort of set the speed of the film that was required for available light photography. Now everybody thought, oh, available light photography would take essentially infinite film speed so no one had even tried it, but now that film speed was in sight with that sort of camera and with a very big lens. So he put together a lens of aperture 0.9 and a shutter of 330 degrees, he got some Autochrome film, 160 speed Autochrome, split 8 millimeter, and he began to take pictures. Sure enough he got excellent pictures in a dark bar, it looked like what you photographed. He couldn’t sell the idea to the marketing people, to the camera people, to anybody. He was getting all these exciting pictures and nobody would pay any attention. At that time, the chairman of the company, Dr. Albert K. Chapman was coming down to the research laboratory once a week and spending all morning and having a review of what was going on. I don’t know of any other company or person in the world like that.
MR. LARSON: That doesn’t happen.
DR. HANSON: It doesn’t happen, but every week he was down there each morning, I mean one morning every week getting familiar with what was going on. One morning he was down there and this fellow, Gorman who was doing the available light was projecting for somebody else. He wasn’t part of the show, but Dr. Chapman had heard him talk once or twice about something he was doing. He looked around and said, “Gorman, what are you doing these days?” He said, “Dr. Chapman, I’m glad you asked. Let me show you this.” So he went and got some of his available light films and he began to talk about what he had done. From then on, the camera people and manufacturing people, and the marketing people were interested.
MR. LARSON: That’s amazing.
DR. HANSON: But Dr. Chapman picked it up and so others began to cooperate and a system was worked out and put on the market. Well apparently, the marketing people had never really quite understood, or never quite got as enthusiastic about it because within a couple of months everything was on backorder. That program went much bigger than anyone expected it to. It was two or three years before we were making enough film and cameras to fill the need.
MR. LARSON: Oh yes. That is amazing.
DR. HANSON: But that was one guy with his idea and it ended from work that he was doing heading in the opposite direction.
MR. LARSON: That’s right.
DR. HANSON: But he followed it right along there. Ok, now we’ve got available light photography, we’ve got the loading camera, the cartridge loading so it’s simple. Now let’s make it really simple. Let’s make the camera small enough to put in your pocket and you have it with you all the time. in fact one of George Eastman’s objectives way back in 1900, he used to say, “I’m going to make the camera as simple as the pocket pencil.” And so that is what we set out to do in the late 1960’s. And by 1972, the pocket camera was put on the market. Now that pocket camera with the little bits of 16 millimeter film, well, when we had come out with the Instamatic, the cartridge load 35 millimeter, we had had to speed up the film and make it less grainy. When you go to the pocket, we had to speed up the film and make it less grainy. That really strained the photographic system, but it was done. In 1972, the pocket camera was put on the market, and it really took off and it made photography available to everybody, children and everybody. Ok. I’m going to sort of step aside and talk about instant photography.
MR. LARSON: Oh yes.
DR. HANSON: Because back in the 1940’s Edwin Lamb developed instant photography, where you take the picture and in 30 seconds you take it out of the camera and you get the finished picture. That was highly successful. He had developed quite a business and he wanted to do that in color. In the late 1950’s, he came to Kodak with some chemistry that would make instant color pictures. Kodak and Polaroid worked together on that for several years. Kodak worked out, perfected the process, and made the Polaroid film which went on the market in the early 1960’s. Well Kodak wanted to have its own color film, own color instant film. None of Lamb’s patents were available to Kodak. So in the late 1960’s Kodak decided, ok, we’ll work out an instant product that it is free from Lamb’s patents and go on the market with our own instant film. A program was set up called PL9-76. This was established in 1968, ‘69, ’70, one of those, I’m not sure. But PL9-76 meant a project of the research laboratory to go on the market in 1976.
MR. LARSON: Oh yes.
DR. HANSON: Thousands of people worked on that in the plant and in the camera area, and in the film, manufacturing and research, in the chemistry, in the physics, and in 1976, the Kodak instant camera went on the market.
MR. LARSON: Oh yes.
DR. HANSON: Now that just shows that if you’re really determined and you do what it takes, you can accomplish a lot of things.
MR. LARSON: Yeah, it’s sort of like we’ll go to the moon by 1970.
DR. HANSON: The moon by 1970, yeah, they really can be done if you set your mind to it. Now whether or not this was a good thing for Kodak to do and sort of take its emphasis off of other things, that’s debatable and people are still debating it. That was a complete success. About this time, I became director of the research laboratories and was not that much personally involved with the work, well fairly closely anyway.
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DR. HANSON: The idea was developed that the film should not be in camera in the roll form, but should be in a disc. There are several advantages to that. It wouldn’t curl. You could advance it easily in the camera and you could have a nice neat small camera, and so work started on a disc camera and I spent my last four or five years at Kodak sort of resisting that program or at least seeing how tough it was going to be to get a good enough picture in the very small film you were going to have in that disc. So as I say, I spent my last few years sort of resisting that program. Well in 19- whenever, oh, where are we? In 1982, the disc camera came on the market. It was a big hit. I was almost right on the quality not being good enough, but it was just good enough, and by now it’s better, so that they made it. So, now everybody has a disc camera and takes simple pictures. Pictures with no problems, automatic advance, fixed focus, you don’t have to focus it. It’s quite a system.
MR. LARSON: Yes, that is so convenient. You just put it in your pocket…
DR. HANSON: Put it in your pocket and it’s there all the time.
MR. LARSON: Women can put them in their purses. When they think about it, and it works out just fine.
DR. HANSON: So that just about brings us up to date with the cameras and the film and where we are today. There are millions of pictures that are made. I use to go around lecturing about the science and development in photography. Back in the 1960’s I remember a statement that I use to make, that I think I’m going to quote right here because I enjoyed it so much. Now I’m going to have to read this. “In 1930, an editorial in the Prim Rose Annual said, and I quote, ‘To imagine that dividends can be paid to shareholders in a process that seeks to supply the public with snapshots, or portraits in color is extreme foolishness.’ Now the 1966 Eastman Annual Report says, ‘According to recent trade estimates, more than 3 billion pictures were made in 1966 by amateur photographers in this country, and 6 of every ten were shot on color film.’ In the April ’67 issue of Photographic Journal, Dr. Hoyd Varden states, ‘There are thought to be 1,350 color finishers of amateur films and prints for the general public. About 900 in plant color laboratories operate for their own needs, including industrial firms, school photographers and so forth. In addition there are 690 known custom color laboratories.’”
MR. LARSON: Amazing developments.
DR. HANSON: After the 1930’s a lot happened.
MR. LARSON: That’s right. That’s amazing.
DR. HANSON: That covers the film and its development and the camera some too. The camera is an important part of taking a picture. An awful lot has happened to cameras in 30 or 40 years. Back in 1938, the photoelectric exposure control was put on the camera by Kodak. That was not successful. Interesting, it was before it’s time and it disappeared for a while, but then it came back and automatic exposure control is a very important part of cameras these days. Rare earth glass was developed in 1941 and that gave a different ratio of index of refraction to dispersion and it made it possible to design better lenses. Aluminized lenses came along in 1946 that cut out the lens glare and that was an important contribution. Then computer designed lenses made it possible to make a very complicated lens in 4 elements that use to take 9 elements. So just playing the use of the computer made a lot of difference to lenses. Aspheric lenses, lens instead of being spherical to the ground, if it could be molded into an aspheric shape, again, that makes it possible to make a simpler lens that’s corrected for astigmatism and achromatic problems and so forth. So, a great deal has happened in the lens design area. Autofocus mechanisms have come along and that has made a tremendous difference in the simplicity and use of a camera. One type of autofocus is sending out a radar signal and then when it bounces back its in focus, but you can’t take a picture through a glass window with that for example. But another kind is maximizing the signal when the picture is in focus, the blacks and the whites are sharply defined and reading the brightness across an image gives you spikes of intensity and maximizing that is a method of telling when you are in focus. So maximizing that measurement is the way that autofocus is done now. The autofocus camera you don’t have to focus, it is just there, its fine. Shutters have been improved so you can get a thousandth of a second or a second, very accurately and that is absolutely necessary. Reflex lenses that you can look in it and see what you’re photographing and not get the wrong picture. Automatic advance of the film, like this disc camera the film advances automatically. You press a button and you’re ready for the next picture. Of course these are all good for the company too. You take a lot more pictures. But all of these mechanics and optics have played a very important role. I’ve mentioned the coating techniques in coating the film. I mean, a tremendous amount of progress has been made in the coating techniques that make it possible to make these films today. All of these advances simplify our taking pictures.
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DR. HANSON: Well I think that just about takes us up to where we are and where photography is these days.
MR. LARSON: Well, that’s been a wonderful exposition of the history of photography so that we got a very complete record there. Perhaps just to round out this whole picture, there was one point there in your presentation where you mentioned the diversion in regard to the defense work during World War II and you, of course everyone in the nation was mobilized including Kodak to assist that. I was wondering if you could to round this whole picture out if you could describe your participation in that to just round out the whole picture.
DR. HANSON: Yeah I’d be very happy to talk about my involvement in the Manhattan Project and Oak Ridge, Tennessee. As I said along the way in 1943, I joined the Manhattan Project. I had seen people from the research laboratory disappearing and people went off on to a project and nobody was told where they were going and I sort of offered my services to Dr. Mees. I said, “I see a lot of people are going out to war. I would be happy to offer my services.” And he said, “Well, gee, I hadn’t thought about you going.” He said, “Ok, sure.” So, I was sent to Berkeley, California, to the radiation laboratory to learn the beginnings of the electromagnetic separation of uranium. I had gotten my degree there and I had known Ernest Lawrence, in fact he had been on my examining committee for my Ph.D.
MR. LARSON: Oh, that’s very interesting.
DR. HANSON: Yeah, so I knew him. I had met Oppenheimer out there at Berkeley during college. [Linus] Pauling I guess he wasn’t involved then, but I had met him. But anyway I went back out to the radiation laboratory to sort of get a basic knowledge of what was going on. Then I went back to Rochester and became involved in some of the chemical operations that were being developed there in the Rochester Research Laboratory. Then very shortly, I came down to Oak Ridge, Tennessee, where I was to become the head of the Chemistry Division of the Tennessee Eastman operation. Tennessee Eastman was operating a plant, the electromagnetic separation of uranium and it was a physics operation, there was an awful lot of chemistry involved, but in the preparation of the whole project, I think the chemistry had not been quite developed as the physics had because it was a physics operation and we had problems.
MR. LARSON: Of course, at that time, the physicists believed the only problems were physics problems.
DR. HANSON: Yes.
MR. LARSON: The others were incidental.
DR. HANSON: Yes, well we had problems that we had to solve as we went along, and we did. We had a wonderful crew of people there, like Clarence Larson and we solved problems that were coming up every day. We made the thing work. I don’t think I need to go into the details of that, but we made the thing work and you know the story of that. Life in Oak Ridge was sort of pleasant, but it was very strenuous. My wife loved it and I loved it. We were the early ones to leave at the end of the war. Dr. Mees had come down to Oak Ridge and asked me to come back to Rochester. They were making some changes in the color photography work and wanted me to come back to Rochester. So I went back to Rochester in May 1945. That was before the final development before anybody knew whether or not we had been successful. I didn’t know any more from then on for a while.
MR. LARSON: But of course at that particular time, the die had been cast, the material had been produced.
DR. HANSON: The material had been produced and delivered.
MR. LARSON: So that the job was essentially done for that particular section.
DR. HANSON: I can remember there were two sections to the plant, the alpha that would enrich the uranium up to 7, 8, finally ten to 12, and the beta that would take it up higher and at first the output of the alpha plant they wanted us to send out to Los Alamos. All we could make we sent out there, until finally they said Ok. Don’t send anymore. So we knew that amount meant something. We can sort of guess that that amount had a meaning to it.
MR. LARSON: Well, that amount that was delivered gave them the numbers that were needed for the final product. So that must have been a very interesting part of your career.
DR. HANSON: It was very interesting. I mean all of us, many of us had some responsibility for people’s behavior and for chemistry and for a lot of things that none of us would have had under any other circumstance. So people grew up pretty fast at Oak Ridge.
MR. LARSON: That’s right.
DR. HANSON: It was a wonderful experience.
MR. LARSON: Yes. And of course you have many of your colleagues then who had come from Rochester and Tennessee Eastman returned including subsequently, didn’t the president or chairman of Eastman Kodak spend some time in Oak Ridge.
DR. HANSON: Yes, he came down. He came down and visited on occasion. Yes he did. Yes. One thing that sort of amused me afterwards was my name could not be in the newspapers or any publicity because my Ph.D. at Berkeley had been with G.S. Lewis and in heavy hydrogen. Now there was no connection between that and what I was doing, but the powers that be had looked up all that sort of stuff and the fact that I had been involved with heavy hydrogen back then meant that my name could not be in any publicity or any newspapers, which I didn’t know at the time.
MR. LARSON: Of course, heavy hydrogen played a role.
DR. HANSON: Yes, in other aspects of it. Yes, it did. Now, the Tennessee Eastman operated this plant, Y-12 plant in Oak Ridge and there were 2 or 300 people that came down from Eastman Kodak Company that were in management positions. Now this story I am about to tell intrigues me as a characteristic of George Eastman and the Eastman Kodak Company that he founded, is at the end of the war, all of the plants that were in Oak Ridge, there was a number of them, and took a vote whether or not the employees would join a union. None of them were unionized, but right after the war, all of the plants took a vote as to whether or not they would join the union. All of the plants except the one run by Tennessee Eastman voted to join the union, and at that plant the people voted not to join the union. Now 2 or 300 management people from Kodak with their policy and the way they handled people and the operation influenced those people that they didn’t need or want a union. Now that tells you something about that company.
MR. LARSON: I think the people all had a sense that they were participating in an important role in the objectives and that feeling of participation meant that their voice was already being heard.
DR. HANSON: That feeling apparently didn’t develop in the employees of other organizations down there.
MR. LARSON: That’s right. That really is a very important point.
DR. HANSON: It’s an important point as far as industrial management is concerned, yes.
MR. LARSON: All right.
DR. HANSON: Yes. Well I think that brings us here.
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